Boris Johnson has proposed banning MPs from acting as paid political consultants or lobbyists, as allegations of Westminster sleaze continue to engulf the Conservative Party.
It came ahead of a vote in the Commons on Wednesday, forced by Labour, on banning MPs from holding some second jobs.
The prime minister is still dealing with the fallout from his failed attempt to block former minister Owen Paterson from being suspended from parliament for breaking lobbying rules.
It led to a series of allegations that many Conservatives were spending too much time on work outside their duties as MPs in order to earn extra money.
Announcing the move on Tuesday afternoon in a letter to Commons Speaker Lindsay Hoyle, Johnson said the code of conduct for MPs needed to “be updated”.
The prime minister said MPs who were prioritising outside interests over their constituents should be “investigated and appropriately punished”.
And he said the rules should be changed to ban sitting MPs from being paid political consultants or lobbyists.
“The vast majority of MP’s of all parties work tirelessly for their constituents,” he said.
“That is why it is imperative that we put beyond doubt the reputation of the House of Commons by ensuring the rules which apply to MPs are up to date, effective and appropriately rigorous.”
The government had previously defended the right of MPs to hold some second jobs.
Johnson’s suggestion came moments before Keir Starmer began a press conference in which he set out his own plan to crack down on Westminster sleaze.