The other is said to be a Tory currently planning to run again in 2014

One potential defector said to be MP due to stand down at general election

Senior Ukip figures are claiming two more Tory MPs are ‘in the bag’ and will be unveiled as defectors within days.

To the alarm of Conservative HQ, Ukip party secretary Matthew Richardson has boasted privately that two turncoats have agreed to switch parties, according to two separate sources.

Mr Richardson has told colleagues an announcement could be made as early as Ukip’s conference, which opens today in Doncaster.

Chris Kelly, pictured left, and Brian Binley, pictured right, both from the Tory party, are two right-wingers who have announced they are standing down as MPs. They are likely to be Ukip targets for defection

One potential defector is said to be a Tory MP who is to stand down at next year’s general election and would sit for Ukip for the next seven months. The other is said to be a Tory currently planning to run again in 2015.

Likely Ukip targets include Chris Kelly and Brian Binley, two right-wingers who have announced that they are standing down as MPs. Others thought to be have been identified by Ukip as potential targets are Gordon Henderson, Mark Reckless and Martin Vickers.

The Conservative whips’ office headed by Michael Gove and in charge of party discipline is understood to be seeking assurances from MPs thought to be likely Ukip targets.

The Conservatives are already braced for Clacton MP Douglas Carswell, who defected to Ukip over the summer, to hold the seat in a by-election on October 9.

If he wins, he will become Ukip’s first elected MP, though a former Tory defector, Bob Spink, sat in the Commons for the party from 2008 to 2010.

While the Tories believe a victory for Mr Carswell is ‘priced in’, further defections would be a shattering blow to David Cameron with a general election just months away. Ukip has previously claimed it has been in contact with eight Tory MPs.

Asked about his reported remarks, Mr Richardson said: ‘I may have predicted that there will be two more people [ready to defect].

'But I don’t know for certain. I can’t talk to you about this for reasons that will no doubt be clear. When Douglas Carswell announced his defection it took us all by surprise.’

Ukip leader Nigel Farage, left, pictured with Clacton MP Douglas Carswell, who defected from Tory to Ukip earlier this summer

Mr Richardson suggested that a recall of Parliament over military action in Iraq or Syria tomorrow could delay any potential announcement.

All of the MPs denied any intention of joining Ukip.

Chris Kelly referred the Mail to the statement on his website saying he stood down because he ‘found it increasingly difficult to find the right balance between my work and my personal and family life’.

He said friends had asked him to join Ukip but he had said no and had not been in any negotiations with them.

A poll by Lord Ashcroft, a Conservative peer and former donor, found Ukip has a 32 point lead on the Tories in Mr Carswell’s Clacton constituency.

His survey, published on the ConservativeHome website, found Ukip had 56 per cent support, while the Tories were on 24 per cent and Labour on 16 per cent. The Liberal Democrats and others were on 2 per cent each.

Almost six in ten of those who voted Conservative at the last general election said they would switch to Ukip, as did 45 per cent of 2010 Labour voters.