The Prime Minister also called for the Commons Code of Conduct to be updated, to be tougher on MPs with second jobs, and for those who fail to focus on their constituents to be “investigated and appropriately punished”.
A Government source said MPs will be given a vote on the proposals in the Commons on Wednesday, as ministers seek to save their blushes by amending a Labour motion that could have forced a similar move.
Sir Keir Starmer said Mr Johnson had been “dragged kicking and screaming” into the new position, which the Prime Minister announced just as the Labour leader was detailing his own plans to tackle sleaze.
The Prime Minister said his proposals would ensure MPs who are “neglecting their duties to their constituents and prioritising outside interests would be investigated, and appropriately punished by the existing disciplinary authorities”.
“They would also ban MPs from exploiting their positions by acting as paid political consultants or lobbyists,” Mr Johnson added.
The move was an attempt to draw a line under the damaging saga that began with the bid, backed by the Prime Minister, to overhaul the disciplinary system to prevent the immediate suspension of Owen Paterson.
Opposition parties forced Mr Johnson into a U-turn over that plan and the Conservative former minister resigned as the MP for North Shropshire while a vote to ban him from the Commons for six weeks for breaching lobbying rules was being rescheduled.
The Prime Minister announced his proposed reforms in a letter to Commons Speaker Sir Lindsay Hoyle, including two key recommendations from the Committee on Standards in Public Life’s report on MPs’ outside interests from 2018.
These included changing their code of conduct so that any outside work should be “within reasonable limits” and “not prevent them from fully carrying out” their duties.
The rules would also ban MPs from accepting paid work as a parliamentary strategist, adviser or consultant, and from accepting payment or offers of employment to act as political consultants.
Mr Johnson said changing the Commons code is “rightly a matter for Parliament” but said he believes those two recommendations would be the basis of a “viable approach which could command the confidence of parliamentarians and the public”.
He announced the move just as the Labour leader began a press conference on bringing a binding vote, to ban MPs taking paid consultancies or directorships, during an opposition day debate on Wednesday.
Without their own strategy, the Government and Conservative backbenchers would have found themselves in the difficult position of having to either back Labour’s plans or face allegations they were not stamping out sleaze.
After wrapping up the conference and retreating to a side room with aides to study Mr Johnson’s letter, Sir Keir told reporters: “Be under no illusion, the Prime Minister has only done this because his back was against the wall because the Labour Party have put down a binding vote for tomorrow.
“This is a significant victory for the Labour Party, it would not have happened if we hadn’t put down that binding vote. This is a Prime Minister who has shown no leadership on this whatsoever.”
Earlier, MPs finally voted to endorse the investigation that found Mr Paterson breached the Commons code of conduct by lobbying ministers and officials for two companies paying him more than £100,000 per year.
Be under no illusion, the Prime Minister has only done this because his back was against the wall because the Labour Party have put down a binding vote for tomorrow
The motion, which was approved unanimously, also undid the proposed changes to shield the Conservative former Cabinet member from a 30-day suspension, which the Prime Minister ordered Tory MPs to back just two weeks ago.
Other senior Conservatives became ensnared in the fallout, with Geoffrey Cox criticised for standing to make more than £1 million by representing the British Virgin Islands in a corruption inquiry launched by the Foreign Office.
The disclosure led to questions over whether the MP for Torridge and West Devon, a practising barrister, was spending enough time on his constituents.
While some MPs in the Conservative Party will back the bid to clean up politics, others will be angered by what could be major restrictions on their ability to earn significant sums outside Parliament.
On Tuesday, former prime minister Theresa May said the Government-backed attempt to save Mr Paterson was “misplaced, ill-judged and just plain wrong”.
She warned the Commons that the U-turn to approve the investigation by Parliamentary Commissioner for Standards Kathryn Stone would “not undo the damage that has been done” to all MPs.