Mr Johnson will bow to pressure from his party and clamp down on MPs with second jobs and those who fail to focus on their constituents.
A government source said MPs would be given a vote on the proposals in the Commons on Wednesday, as ministers seek to avoid embarrassment by amending a Labour motion that could have forced a similar move.
Opposition leader Sir Keir Starmer said Mr Johnson had been “dragged kicking and screaming” into the new position after allegations of inappropriate behaviour against the Conservatives.
Mr Johnson 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,” he said.
The move was an attempt to end the damaging saga that began with the bid, backed by the Mr Johnson, 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 parliamentary strategists, advisers or consultants, and from accepting payment or offers of employment to act as political consultants.
Mr Johnson said changing the Commons code was “rightly a matter for Parliament”.
But he said he believed 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 Mr Starmer was due to announce bringing a binding vote on banning MPs from taking paid consultancies or directorships, during an opposition day debate on Wednesday.
Without their own strategy, the government and Conservative backbenchers would have been in the difficult position of having to back Labour’s plans or face allegations they were not stamping out inappropriate behaviour.
“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," Mr Starmer said.
“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.”