A Cabinet minister has sidestepped questions on whether the Chief Whip should resign over a voting pact row.

Karen Bradley said Julian Smith had made an “honest mistake” when he ordered Tory Party chairman Brandon Lewis to break a pairing agreement with an MP on maternity leave during a crucial Brexit vote.

But the Northern Ireland Secretary, a former whip, twice declined to say if his job was at stake.

Asked if Mr Smith is going to have to resign, Ms Bradley told BBC Radio 4’s Today programme: “Well, you know, I know everybody is fascinated by the workings of the Whips’ Office.

“House Of Cards has always been a pretty successful programme, in my experience.

“But I was a whip, I can tell you that, at the point where you have a number of difficult votes – and let’s be clear, over the last few days we have had a dozens, it turns out, of difficult votes – mistakes happen.

“It was an honest mistake. The Chief Whip has apologised.”

Pressed again on his future, she said: “As I’ve said, he has apologised.”

Meanwhile, when asked if Mr Smith should resign, Defence Secretary Gavin Williamson, a former chief whip, said: “No, I don’t.”

He added: “I haven’t got any of the details as to what’s happened, but what the Government has been absolutely committed to doing is actually delivering the will of the British people, which was given in terms of the referendum, and that is what this Government will deliver on as we exit the European Union.”

Mr Lewis had been “paired” with Liberal Democrat deputy leader Jo Swinson, meaning neither would walk through the voting lobbies.

Tory sources said the move had been an error but admitted the Whips’ Office had considered breaking other pairing arrangements during the vote.

The decision to delve into dark arts tactics during the knife-edge Brexit battle on Tuesday drew criticism from across the political divide.

Tory former minister Anna Soubry joined Labour in calling for Mr Smith and Mr Lewis to resign.

Theresa May insisted they had made an “honest mistake” and had apologised.

Speaking to the Press Association during a visit to Northern Ireland on Thursday, the Prime Minister said: “An honest mistake was made here and both the Chief Whip and Brandon Lewis have apologised to Jo Swinson, the member for East Dunbartonshire, about that.

“As I say, it was an honest mistake and they have apologised.”

The PM repeated this line when pressed on the issue during a question-and-answer session following a speech in Belfast on Friday morning.

Over the course of the Parliament, 66 pairing arrangements have been broken, with 52 of those at the hands of the Opposition, according to Tory sources.

Conservative whips did consider breaking short-term pairing arrangements – those for MPs who need to be away for another engagement, sources acknowledged.

But they said long-term pairing for maternity and health issues was something they stick to and insisted breaking the agreement with Ms Swinson had been a mistake.

Commons Leader Andrea Leadsom said there would now be a debate on proxy voting, which would end the need for pairing, in September.