Later, during an appearance at the liaison committee, Caroline Nokes, the MP who has accused Mr Johnson’s father, Stanley Johnson, of touching her inappropriately, challenged the Prime Minister over whether more should be done to give women the confidence to report sexual harassment.
MPs on Wednesday voted through Mr Johnson’s proposals for tightening the rules on which second jobs they can hold – a move Number 10 hopes will ease the political pressure.
It means plans to ban MPs from becoming political or parliamentary “consultants” and capping their outside work to within “reasonable limits” will be taken forward by the cross-party committee on standards.
However, the exact details of what would and would not be allowed remained unclear on Wednesday, with specific changes to the MPs’ code of conduct due to be made public before the end of January.
Disquiet remains in the Tory party over the moves, with some MPs telling The Telegraph they want to ban Mr Johnson and other Cabinet ministers from getting paid political jobs when they leave office in return.
Over the past fortnight there has been widespread frustration among Tory MPs over how a botched attempt to help Mr Paterson spiralled into a wider debate on MPs, their second jobs and standards in politics.
The Prime Minister was questioned at the liaison committee about his handling of the Paterson case. He had refused repeated opportunities to express regret, but on Wednesday – while he did not explicitly apologise – he accepted blame.
He told the committee: “The intention genuinely was not to exonerate anybody, the intention was to see whether there was some way in which, on a cross-party basis, we could improve the system. In retrospect it was obviously, obviously mistaken to think we could conflate the two things – and do I regret that decision? Yes, I certainly do.”
Mr Johnson also said it was “clear” that Mr Paterson had broken lobbying rules. He said: “In forming the impression that the former member for North Shropshire had not had a fair process, I may well have been mistaken.”