“The key point is going to come when the privileges committee determines if the Prime Minister deliberately misled the House of Commons. If it does, that is when the pressure will become unsustainable,” said the source.
Asked at the G7 summit in Germany on Sunday whether his ambitions for a third term were delusional, Mr Johnson said: “What I’m saying is this is a Government that is getting on with delivering for the people of this country and we’ve got a huge amount to do.”
He said the “golden rule” was to “focus on what we are doing” and maintained the achievements of his Government had been “exceptional” and “remarkable”.
Brandon Lewis, the Northern Ireland secretary, doubled down on the third term claims, saying; “Looking long-term is a really good thing.”
Rebel MPs claimed on Sunday that allies of Mr Johnson had raised the spectre of a snap general election in October. “I was told we are not going to have an election in October on the proviso that the party behaves itself,” said one leading rebel.
“It’s a threat to say effectively the Prime Minister would prefer to take the whole ship down rather than put himself overboard in a dinghy.”
Tim Loughton, a former minister and critic of Mr Johnson, said he was opposed to a rule change, adding: “The surprising thing is that we have not seen more ministerial resignations and it is probably that that will create momentum.
“If he can survive and get his attention back on the people’s prioritiesthen he needs to have a radical shake-up of Government and bring in a lot of critics. I want to see people who are not saying ‘Yes, Prime Minister’ but saying ‘Are you nuts, Prime Minister?’ taking him on and challenging him on certain things.”