Nigel Farage’s Brexit Party has claimed victory in the European parliamentary elections, taking 29 seats and topping the poll in ten of the UK's 11 regions.
On a grim night for the Conservatives and Labour, the pro-EU Liberal Democrats emerged as the other big winners, with leader Sir Vince Cable saying it was “proof that the Lib Dems are the biggest, strongest voice of Remain”.
Theresa May said it was a "very disappointing night" for the Conservatives and once again urged MPs to find a solution to the Brexit crisis.
"Some excellent MEPs have lost their seats, some excellent candidates missed out," she said.
"But Labour have also suffered big losses. It shows the importance of finding a Brexit deal, and I sincerely hope these results focus minds in Parliament"
Boris Johnson, widely considered the frontrunner in the race to replace Ms May, said voters had delivered the Conservative party with a "final warning".
He urged his colleagues to deliver Brexit and "deliver Brexit and set out our positive plans for the country."
At the same time Labour edged closer to support for a second Brexit referendum, after voters in Remain strongholds deserted the party and voted for the Liberal Democrats.
In early-morning messages after seeing the party slump to third place with a 14 per cent share of the vote, both Jeremy Corbyn and shadow chancellor John McDonnell said that the issue of EU withdrawal must be put to a public vote – which could come in a general election or a Final Say referendum.
Mr McDonnell tweeted: “Can’t hide from hit we took last night. Bringing people together when there’s such a divide was never going to be easy. Now we face prospect of Brexiteer extremist as Tory leader and threat of no deal, we must unite our party and country by taking issue back to people in a public vote.”
If you would like to see how the EU election results night unfolded, please see what was our live coverage below:
Good afternoon and welcome to The Independent's European elections live blog.
We'll be providing live updates on all the results as we get them. Stay tuned.
The polls are still open in many countries, but here is a roundup of some of the key expectations for the night ahead and what the results could mean for the future of the EU and its member states:
Nationalists expected to make gains across EU in European elections, with mainstream parties hoping to cling to power
Germany, France, Spain and Italy among countries going to polls today ahead of results on Sunday eveningFrance's Interior Ministry says turnout for the European parliament election was up in the country compared to previous vote.
In France, turnout was over 43 per cent at 5pm (3pm GMT), compared with 35 per cent at the same time in 2014.
Polls remain open until 8pm in the country's big cities.
Several French poll institutes estimate the final turnout may be over 50 per cent at the end of the day, which would be a first in the country since 1994.
A similar rise in turnout has been observed in neighboring Spain and Germany.
In the whole European Union, turnout for this pan-European vote has trended downward since the first election in 1979.
Turnout stood at less than 43 per cent in the 2014 vote.
Spain's Interior Ministry has said turnout for the European elections is up to 49.3 per cent from nearly 34.1 per cent in 2014.
Spain was also holding local and some regional elections on Sunday, including the highly watched races for the mayor of Madrid and Barcelona.
In Barcelona, a Catalan separatist candidate was trying to oust its incumbent far-left mayor, who said she does not support secession but believes Catalans should vote on the question.
Italy's anti-refugee interior minister Matteo Salvini has said he feels a "change in the air" and a win by his right-wing League party would "change everything in Europe".
Mr Salvini's League is seeking to form an alliance of nationalist, populist parties to exert more power in the European parliament over the affairs of the European Union.
He has campaigned relentlessly throughout Italy and has become the face of Europe's far-right by speaking out against refugees and the influence of Muslims in Europe.
The League party, once just a regional power in northern Italy, is gaining strength throughout the country. It is the junior partner in a coalition government with the populist Five-Star Movement, but the coalition is on rocky ground.
Labour is braced for a "good kicking" in the European parliament elections, shadow chancellor John McDonnell has said.
His comments come after deputy Labour leader Tom Watson said the party must "find some backbone" and fully commit to a second referendum on Brexit to have any chance of winning the next general election.
Mr McDonnell said he understood Mr Watson's frustration, but the party had been right to "tread a really difficult road" of trying to bring Leave and Remain supporters back together.
The shadow chancellor said Labour would pay an electoral price for that stance when European parliament results begin to be announced late on Sunday.
Mr McDonnell told Sky News: "I think we most probably will get a good kicking in the election results tonight. We'll see. We are braced for that."
Mr Watson said he feared the results of the European elections would show voters had deserted the party and blamed Labour's ambiguous position on a public vote.
The party must stop "hedging its bets" and urgently rethink its stance in order to realign itself with its members, he added.
Writing in The Observer, he said: "For our party's sake, but most of all for Britain's sake, Labour needs to find some backbone on Brexit, find our voice - and do it fast."
He added: "Our performance (in the European elections) is a direct result of our mealy-mouthed backing for a public vote on Brexit when it is being demanded loud and clear by the overwhelming majority of our members and voters.
"Polls show Labour has been losing up to four times more voters to parties giving full backing to a people's vote than to (Nigel) Farage.
"And those same polls show we would have beaten him by a country mile if we had unambiguously backed a public vote on any form of Brexit.
"Once results are in, we must channel our frustration into winning those voters back. Never again can Labour policy on the most crucial issue of our generation be on the wrong side of its members and voters."
Mr Watson described the party's stance on a second referendum as "a deliberate, self-defeating attempt to triangulate between different groups".
An EU parliament spokesperson has said turnout for 27 nations excluding UK is nearing 51 per cent, according to early figures - the highest in at least 20 years.
Hungary's prime minister has said he hopes the European parliament election will bring a shift towards political parties that want to stop migration.
Viktor Orban said after casting his vote at a school near his Budapest home on Sunday that the issue of migration, which he believes is stoppable, "will reorganise the political spectrum in the European Union".
Councils in some areas have reported increased turnouts at this year's European elections.
The turnout for the South East is 39.36 per cent which was up from 36.3 per cent in 2014, while in Birmingham it had dropped from 32.4 per cent to 31.1 per cent this year.
In the South West, a turnout of 40.5 per cent has been recorded - three percentage points up on 37.4 per cent from 2014 while the North East has 32.7 per cent, slightly up on the 31.6 per cent of 2014, and Eastern had 36.4 per cent, much the same as the 36.6 per cent of 2014.
The turnout in Wales was five percentage points up on 2014 - 37.3 per cent as against 32 per cent in the previous Euro poll.
However, the turnout for Northern Ireland, at 45.1 per cent, was down from 51 per cent in 2014.
France's far-right nationalist leader Marine Le Pen has declared victory in the European elections over president Emmanuel Macron’s party.
UK turnout figures are expected later on Sunday evening, as final tallies roll in for an election both centrist parties and the far-right have portrayed as a referendum on sovereignty and the European Union.
Four days of voting will end on Sunday, after 426 million people across 28 nations were eligible to vote for the makeup of the European parliament.
In Britain, voters were electing MEPs who will lose their jobs when Brexit is finalised.
The leader of Spain's upstart far-right Vox party, Santiago Abascal, asked Spaniards to make "their voice heard" after he cast his ballot in Madrid.
"We come to these elections calling for participation from all Spaniards in accordance to their convictions and principles," Mr Abascal said.
"We want to tell them that it is important that each Spaniard has their voice in the municipal and regional institutions, also in the European institutions as, often, this is not seen with much interest by citizens."
Vox erupted into the Spanish political scene in December when it won its first seats in the regional legislature for the Andalusia region. It then won 10 per cent of the vote in national elections on 28 April to enter the Spanish parliament.
Founded in 2013, Vox failed to win a seat in 2014 European elections, its first electoral test. Unlike other European far-right parties, Vox is not anti-European Union despite its ultra nationalist ideology.
The center-right candidate to lead the European Union Executive's Commission has promised to bring "stability" to the European Union over the next few years and predicted pro-EU forces will lead the next parliament.
Manfred Weber, the candidate of the European People's Party, said in Berlin that Sunday's European parliament elections appeared to have weakened the political centre.
He said it is "most necessary for the forces that believe in this Europe, that want to lead this Europe to a good future, that have ambitions for this Europe, ... (to) work together."
He said those forces have to have a "clear division" from other political groups who oppose Europe on both the right and the left.
Mr Weber said the EPP will be "hopefully the strongest group" in the new European parliament. He said "we promised stability, and (we) will guarantee this stability in the coming years."
The highest turnouts by local authority in the West Midlands were Malvern Hills with 43.27 per cent, Stratford on Avon with 42.49 per cent, and Warwick with 42.04 per cent.
The lowest turnouts were in Stoke on Trent with 26.53 per cent, Sandwell with 27.93 per cent and Walsall with 28.72 per cent.
The regional voting turnout figure for London in the European Elections is 41.3 per cent, up from 40.1 per cent in 2014.
All 32 boroughs and the City of London have finished counting votes, the regional returning officer Janet Senior said.
French president Emmanuel Macron's party's pledged to combat nationalists at the European parliament and block them from weakening France.
The lead candidate of Mr Macron's centrist party, Nathalie Loiseau, urged all pro-European forces "to unite to defend the interests of the Europeans" and not let the European Union fall into the hands of "those who want to unbuild it".
In Yorkshire the local authorities with the highest voter turnouts were Harrogate with 42.78 per cent, Craven with 41.57 per cent and Hambleton with 40.68 per cent.
The lowest turnouts were in Hull with 24.04 per cent, Barnsley with 27.91 per cent, and North East Lincolnshire with 28.65 per cent.
Greek Prime Minister Alexis Tsipras is likely to call snap elections in June, a source in his Syriza party has told Reuters.
Syriza, in power since 2015, appear to have suffered a heavy defeat on Sunday in elections, trailing behind the main opposition New Democracy party. The leader of the New Democracy party has called on Tsipras to step down.
