As succession rumours intensify, with Cabinet ministers accusing the chancellor of plotting, Business Secretary Kwasi Kwateng defended Rishi Sunak this morning saying he is “a hundred per cent behind the Prime minister”.

Speaking to Sky News’ “Trevor Phillips on Sunday”, Mr Kwarteng, who was there first-and-foremost to discuss the energy crisis, said “I was with Rishi Sunak in the House of Commons for nearly an hour and a half last week as he unveiled a really good set of measures to help people”. He added, “Why I’m mentioning that is that we’re working together”.

This comes at the end of a fast-paced and difficult week in government, which has seen pressure on the prime minister rise further. Sir Charles Walker MP, a former vice-chairman of the 1922 Committee of backbench Conservative MPs, said yesterday that it was now “inevitable” that Conservative MPs would remove him from office over the “partygate” scandal.

Commenting on this, Mr Kwarteng said: “I don’t know where Charles Walker’s coming from, I don’t see what he’s seen. He’s entitled to his view as I’m entitled to mine”. He added that “lots of people say things are inevitable and they never happen”, insisting: “We just have to wait and see”.

At the centre of the mounting pressure on Mr Johnson is his own chancellor, Mr Sunak, who distanced himself this week from the PM’s comments linking the failure to prosecute Jimmy Savile  with the conduct of the Leader of the Opposition, Sir Keir Starmer. It is unusual for a Chancellor to so openly distance themselves from a sitting PM, and three members of the cabinet have said the chancellor should be sacked for disloyalty.

According to reports in The Sunday Times, one Cabinet Minister said: “Rishi has been far too blatant this week”. “He’s a bit like a five-year-old boy who tells the girl he likes to ‘please, please’ not kiss him. He appears to be trying to hasten the PM’s departure before things get properly shit with the economy”. Another reportedly said they had been “flabbergasted” by his behaviour and his “blatant plotting”.

Asked whether he would have used the comments linking Jimmy Savile and Sir Keir, Mr Kwarteng said it “depends what the context was”. He added: “In that context, [the House of Commons], I think it was entirely reasonable”. Mr Kwarteng pointed to the fact that Sir Keir had apologised on behalf of the Crown Prosecution Service over the affair, suggesting that this is how “accountability” and “leadership” work. Mr Kwarteng said: “In that context I think it was perfectly reasonable to mention the fact that Sir Keir had apologised. Keir himself apologised on behalf of the organisation that he led about the fact that they failed to prosecute Jimmy Savile”.

Mr Kwarteng added: “I’m not saying that he had personal blame – he didn’t, and we’ve been very clear about that”. Asked again if Boris Johnson should have apologised for the comments, he said: “I think he clarified what he said – he was very clear that Sir Keir did not have personal responsibility”.

Alongside Rishi Sunak, Health Secretary Sajid Javid also distanced himself from these comments in the past week.

Questioned over the PM’s future, Mr Kwarteng said Mr Johnson is “committed to delivering the agenda” put forward by the Conservative party. “I spoke to him earlier in the weekend and we’re very focused on making sure that we have a strong economic recovery”, he added.