After news emerged that the Prime Minister would not be taking part in a BBC debate with other party leaders on Wednesday evening, Mr Farage said she had become a “liability” for the Tories because “the more people see of Mrs May, the less they like her”.
Writing in the Telegraph, the former Ukip leader said: “I said from the start that I doubted her sincerity, that she was prone to shifting positions and that it would be difficult for a Remainer leading a Cabinet of some very strong Remainers to carry off the Brexit election without some friction.
Nigel Farage believes Theresa May is becoming a 'liability' for the Tories
She looks insincere and really rather cold compared to Mr Corbyn who, despite his mistakes and appalling historical associations, appears to be having a ball
“Perhaps we’ve been given a clue in the recent Budget, where within a few days the National Insurance rises for the self-employed were abandoned.
“But even more astonishing than that, for the first time that anyone can remember, a manifesto pledge on social care was changed even before we reached the election.”
He branded the Tory manifesto a “disaster” and said the party’s U-turns on National Insurance increases and social care show the Prime Minister is “a weathervane and not a sign post”.
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Jeremy Corbyn during a visit to Hackney Marshes Football Pitches, to highlight Labour's manifesto commitment to ensure 5% of the Premier League's television rights income is diverted to the grassroots game, during a General Election campaign
Mr Farage went on to say Mrs May’s Brexit rhetoric was initially a vote-winner, but after refusing to directly answer Jeremy Paxman when he asked if she believed in Britain’s EU exit, concerns have been raised among the electorate.
He added: “As voters see her repeated U-turns on other policies they are beginning to ask: ‘How can you lead the country through a tough set of negotiations if you don’t really believe in what you’re doing?’
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Amber Rudd stood in for Theresa May as the Tories' representative for the debate
“I still believe that Brexit is her strongest card. Indeed given her failures as Home Secretary over immigration and tackling terrorism, it may be her only card.
“And the more times she says no deal is better than a bad deal the better. But does she really believe it?
“She looks insincere and really rather cold compared to Mr Corbyn who, despite his mistakes and appalling historical associations, appears to be having a ball.
Farage pictured during a speech in Portugal on Tuesday
“While there is huge criticism of her lack of courage in attending the leader’s debate, I sense from the Tory perspective it was the right decision. I expect we will see a lot more of David Davis and Boris Johnson in the last few days. Too much more of Mrs May and it could be a hung Parliament.”
Mrs May’s bid to increase her Commons majority has been plunged into chaos after a recent poll showed the Labour party have reduced the Conservatives’ lead to just three points with only a week to go until the General Election.
The YouGov poll for the Times, conducted over past two days (May 30-31), puts the Tories on 42 per cent with the Labour party close behind on 39 per cent.
The Tories three point lead is the lowest of the campaign so far, while Labour’s 39 per cent is the party’s highest poll result since February 2014.
The pollster, who garnered responses from 1,875 British adults, put the Lib Dems down two points on seven per cent, with Ukip behind on four per cent.