Votes are being counted in the Rochester and Strood by-election, with Ukip confident of taking a second seat from the Tories, but perhaps by a narrower-than-predicted margin.
Mark Reckless appeared poised to join fellow defector Douglas Carswell by returning to the Commons to represent the seat he won as a Tory in 2010 under the Eurosceptic party’s banner.
Ukip leader Nigel Farage predicted that the result would be tighter than the significant margins suggested by opinion polls and a cabinet minister said the Tory vote was “holding up well”.
A narrow loss may ease nerves in the Conservative ranks that other Eurosceptic waverers in the ranks will jump ship and join them, with one right-wing backbencher ruling it out and another saying it would be “insane”.
And David Cameron was handed a boost after newspaper headlines were grabbed not by his expected bloody nose at the hands of Nigel Farage, but by a senior Labour MP quitting the shadow cabinet.
Shadow attorney general Emily Thornberry stepped down after apologising for tweeting what was criticised as a “snobbish” picture of a house in the Kent constituency draped with England flags.
Conservative work and pensions s secretary Iain Duncan Smith accused her of “sneering at the electorate of Rochester” and said it showed Labour “doesn’t even respect the people they expect to vote for them now”.
Blow for Cameron
Defeat — however narrow — would be a particularly wounding blow for prime minister David Cameron who has personally spearheaded a concerted fight for a seat his party had claimed just weeks ago it had a good chance of holding.
And Mr Farage, whose party’s dramatic surge has undermined Mr Cameron’s chances of returning to Downing Street in next year’s general election, said a Ukip victory would put the result of the 2015 poll “up in the air”.
“I feel our vote is solid. I think we are going to win but I think it’s maybe closer than people think,” he said.
Mr Duncan Smith declined to accept defeat despite Tory sources suggesting the party had no hope of winning, insisting he thought the Conservative vote was “holding up pretty well actually”.
“Labour, expected to come in a distant third, ran a low-key campaign and sought to play down the significance of the by-election for its general election prospects, pointing out it did not need to seat to secure a Commons majority.
But it found itself thrust embarrassingly into the spotlight over Ms Thornberry’s picture.
The Islington South and Finsbury MP posted the image of the modern terraced house with three red and white Cross of St George flags and a white van in the drive along with the message “Image from Rochester”.
After a social media and political backlash, she apologised after being given a dressing-down by leader Ed Miliband and Labour later announced that she had resigned as shadow attorney general.