Boris Johnson has suffered a blow to his campaign for the Tory crown after party grandee William Hague backed his rival Jeremy Hunt.
The former Conservative leader warned that Mr Johnson's Brexit strategy could destroy the party, saying his pledge to leave the EU by 31 October on a "do or die" basis had cost him a vote, as 'do and then die' could very easily be the outcome".
Both Tory leadership hopefuls faced pressure over Brexit at a hustings in Belfast as the contest enters its final weeks.
To follow events as they unfolded, see our live coverage below

Tory leadership hopefuls Boris Johnson and Jeremy Hunt will face a grilling over their Brexit plans at a hustings in Northern Ireland this morning.
The pair will visit Belfast as part of their quest to win over party members, who will decide the next Conservative leader.
The session will undoubtedly focus on their proposals to resolve the Irish border issue and remove the controversial backstop.
Boris Johnson's campaign has suffered a blow after Tory grandee William Hague threw his weight behind his rival.
Lord Hague, a former Tory leader, said that Mr Johnson's pledge for Britain to leave the EU by 31 October on a "do or die" basis had cost him a vote.
"In doing so, however much I wish him well if he is elected, he has lost my vote, because 'do and then die' could very easily be the outcome", he wrote in the Daily Telegraph.
"Both men have great merits. But asked to weigh who might make the better prime minister, and have the best chance of avoiding calamity over Brexit, I come to a clear conclusion.
"I will mark my ballot for Jeremy Hunt."
Team Boris has dismissed reports that Mr Johnson is planning to shrink the size of the cabinet by merging Whitehall departments.
Justice, Business, Culture, International Trade, Work and Pensions, Transport, and Brexit could all be axed or merged with other departments under plans being championed by members of Mr Johnson’s team, according to the Daily Telegraph.
Supporters include Dominic Raab, the former Brexit secretary, Andrea Leadsom, the former leader of the house, Chris Heaton-Harris, the former Brexit minister, Liz Truss, the Chief Secretary to the Treasury, and Priti Patel, the former international development secretary.
A campaign source told The Independent it was "absolute nonsense".

What have Johnson and Hunt promised on taxes and spending and where would the money come from? Our business editor Olesya Dmitricova has run the rule over their pledges.
An investigation has been launched into whether senior civil servants said they thought Jeremy Corbyn was "too frail" to be prime minister, Downing Street has said.
Theresa May's official spokesman told a Westminster briefing: "The Cabinet Office is investigating this potential breach of the civil service code fully and fairly just as it would any other.
"If we are able to identify an individual responsible we will take disciplinary action."
Asked about the Labour leader's call for an independent probe, the PM's spokesman said: "We are taking the matter extremely seriously.
"The civil service is responsible for looking into any potential breaches of the civil service code and this is no different."
With PM stuck in Brussels, her spokesman was asked if she was "frustrated" by the seemingly never-ending discussions over the EU's top jobs.
He said: "The prime minister fully understands that while we are a member of the EU we have rights and obligations that are part of that - and one of those is to attend European Council".
However, he deflected a question about whether she would become "more involved" to try to reach a decision, saying only - again - that she would be "as constructive a partner as possible".
Jeremy Hunt is first up at the hustings in Belfast, which you can watch here.
He starts by praising the peace process in Northern Ireland as a 'very significant part of our country's history' and says he knows how much people admire the achievement around the world, as foreign secretary.
He says he is best placed to achieve a Brexit deal because of his own business background. Hunt has made much of his time as an entrepreneur during the contest.
He sets out his four priorities - to turbocharge the economy, to bolster defence spending and make Britain strong on the world stage, to abolish illiteracy and boost education, and to get more young people supporting the Tories.
Hunt says getting Brexit wrong could threaten democracy and the future of the Tory party, but get it right, and it will create a brighter future.
Now to the Q&A.
Jeremy Hunt is asked why Northern Irish politicians were allowed to draw a salary when the Northern Ireland Assembly is not sitting. He says it is totally wrong and he would become personally involved in the Stormont talks if he was in charge.
On the backstop issue, he says he recognises there will never be a deal to leave the EU including a backstop so 'it has to change or it has to go'.
Hunt says the problem is not border infrastructure on the island of Ireland but the fact the UK would be trapped in EU customs rules. He says he argued against the backstop in cabinet but kept his concerns to himself out of loyalty to Theresa May.
He says it will be a technology-based solution and could be an invisible border like in Germany. He says the EU would rather the UK was within the customs union, which is it claims there is no technology in existence.
Jeremy Hunt is asked if he is trying to 'out-Boris Boris' by being more pro-Brexit.
He denies this and says the difference between them is he is prepared to delay Brexit for a short while if necessary to get a deal, whereas Boris Johnson has set down an 'absolutist' deadline.
Asked what the difference is between Boris' 31 October deadline and his own suggestion that he would end talks by end of September, he says he wants to give the EU a reasonable period to consider his proposals.
Hunt is asked about disparity between British and Northern Irish laws on same-sex marriage and abortion, he says this shows how important it is for the Assembly to be revived. He says he would want the law changed if he was Northern Irish.
Hunt praises Tory members in Northern Ireland - where there are no Conservative MPs - and says he will back them if he is PM.
Asked about the DUP £1bn deal, Hunt says he hopes the DUP will support the government on Brexit.
In response to another question on Brexit, Hunt admits it will be 'bumpy getting there' in getting a deal but it is possible.
A Tory audience member says Nigel Farage is a 'highly competent operator' and questions whether they can use learn from his expertise.
Hunt says Farage wants a different outcome, a no-deal Brexit. This would be bad for Northern Ireland, he says.
And that's it from Mr Hunt.


