Conservative chief whip Michael Gove has hit back at Ukip claims that two MPs are on the verge of joining Nigel Farage, saying he is “absolutely 100%” sure there will be no more defections in the wake of the Rochester & Strood byelection.

The senior Tory, who is in charge of party discipline, said he is “quite confident” his party will win, despite all the polls over the last seven weeks suggesting Ukip is on course to have its second MP. One bookmaker has even started paying out on a victory for Mark Reckless, the former Tory MP whose defection to Ukip triggered the contest in the north Kent constituency.

As voters went to the polls, Gove dismissed the claims by Reckless that there are two Conservatives considering whether to jump ship if Ukip win the crucial byelection.

Any more defections, following those of Reckless and Ukip’s first MP, Douglas Carswell, are likely to provoke a crisis in the Conservative party about the haemorrhaging of support and potentially provoke a move on David Cameron’s leadership.

Asked about the MPs who may be plotting a switch in allegiance, Gove said: “There aren’t any. I’m one of the MPs Mark Reckless has spoken to in the last seven weeks. I bumped into Mark and said hello during the course of the campaign, so I must be one of the two. No one’s going to defect… I’ve talked to lots of different people across the party. I’m absolutely 100% convinced no one else will defect.”

He added: “I’ve got a £50 bet on the Conservatives winning so I hope I will be able to wipe the smile off the bookmakers’ face later. I’m quite confident… I am hopeful that we will win and confident that we put up a good fight. We’ll see what happens at the count. But I feel fairly confident on the basis of what I’ve seen.”

Cameron has taken a different tone to Gove in recent days when asked about the prospect of defections. Asked about his message to would-be switchers, he urged MPs to stay with him on the basis that moving the Ukip would be “counter-productive” when he has already promised a referendum on Britain’s membership of the European Union.

Reckless heaped pressure on his former bosses in the Conservative party on Wednesday night by claiming he had held talks with two of his former colleagues about them making the same move.

Reckless said: “During the campaign I have spoken with two Conservative MPs about the possibility of their moving over and I think they will want to see what the result is before making any decisions. One of them I had discussions with by telephone and the other I met in an undisclosed location, not in the constituency. It is a very individual decision. And I feed back to Nigel [Farage] on those conversations.”