London mayor election: First results suggest Ulez could still be problem for Sadiq Khan

Meanwhile in Wandsworth the Conservatives gained a council seat from Labour, sweeping to victory in the West Putney by-election.

Kelly Martin held the Hillingdon East ward for the Tories with 58.1 per cent of the vote. He increased the party’s vote share by a tiny 0.6 per cent. Turnout was high for a council by-election at 46.58 per cent.

One Tory source told the Standard that the result showed anger at Mr Khan’s expansion of the Ultra Low Emission Zone last year was still “extremely prevalent” in London’s outer boroughs.

“The polls show that Sadiq should walk this election but anger at Ulez is still extremely prevalent and this vote shows that,” they added. “It could cause real upset for Labour.”

Labour blamed the Ulez expansion scheme for its by-election defeat in Boris Johnson’s former seat last year. The party had hopes of winning the Uxbridge and South Ruislip constituency in Hillingdon and polls ahead of the vote in July had Labour eight points ahead.

But Tory candidate Steve Tuckwell managed to retain it for Rishi Sunak’s party.

Speaking after the results were announced, Labour frontbencher Steve Reed, said: “I think the winning Conservative candidate just said it, didn’t he? He said that if it wasn’t for Ulez, he believes Labour would have won this by-election.”

Across England the Conservatives have suffer a set of dire results in overnight local election counts.

Labour won the Blackpool South parliamentary by-election with a swing of 26.33 per cent from the Tories, the third biggest since the Second World War.

Mr Khan is the favourite to win the London mayoral election and secure a third term leading City Hall. Polls before Thursday’s vote put him between 10 and 20 points ahead of his Tory rival.

Londoners’ votes for the Mayor of London, London Assembly Constituency member and London Assembly London-wide member contests will be verified and counted over the two days after polling day on Thursday, 2 May.

But it will most likely be early afternoon on Saturday at the earliest when it will become clear whether Mr Khan has won or if Ms Hall has pulled off a surprise victory.

Hillingdon By-Election Results

West Putney Ward By-Election