As a Cabinet minister, he was one of those involved in the mammoth five hour meeting at Downing Street on Wednesday on the Withdrawal Agreement.
And it was widely rumoured that he would be resigning his role due to concerns over future fisheries policies after Brexit.
However, despite some of his colleagues quitting, he was yesterday still standing firm and said he was “absolutely committed” to the integrity of the UK and would not be part of the “soap opera of resignations”.
He added: “I also take very seriously the job of ensuring Scotland and the UK gets the best possible Brexit that does not also threaten the integrity of the UK and that’s what I’m still committed to doing. “I’m not going to be bounced into resigning.”
Meanwhile, Mr Mundell also issued a statement on Wednesday’s meeting, clarifying his decision to support the Prime Minister. It read: “I was content to move to the next stage of the process on the basis that Brexit will deliver for our fishing industry – as I and colleagues set out in our letter – and on the basis that arrangements for Northern Ireland will not undermine the economic or constitutional integrity of the UK. I hope there will be agreement at the European Council later this month and we can move to a vote in Parliament. “The worst possible outcome for Scotland and the whole of the UK would be a no deal departure from the EU.”