The Commons standards watchdog has backed down on its call to be able to investigate MPs who bring parliament into disrepute through behaviour in their "private and personal" lives.
The independent parliamentary commissioner and cross-party standards committee called three years ago for the code of conduct to be widened to cover such behaviour.
However, the proposals were voted down by MPs in March 2012, amid concerns that they had the potential to be too intrusive.
Since then the committee and MPs have been engaged in a stand-off on the issue, with the Leader of the House refusing even to schedule a debate.
As a result a raft of other changes to the Guide To The Rules, designed to tighten controls on lobbying and declaring interests, have been effectively stalled.
The existing code of conduct, which dates from 2009, explicitly states that it "does not seek to regulate what members do in their purely private and personal lives".
The commissioner and committee previously recommended adding the caveat "unless such conduct significantly damages the reputation and integrity of the House of Commons as a whole or of its members generally".
But in a new report, the committee accepted that it had not reassured critics of the move by suggesting a "safeguard" that it would have to give express consent for an investigation to be launched.
"We understand that the reason the changes in the guide have still not been debated is that there are concerns about a related proposal to amend the code of conduct," the report said.
"The debate in the House on 12 March 2012 and our subsequent discussions suggest that those who wish to restrict the commissioner's power to investigate have a narrow view of what would be purely private and personal behaviour.
"In practical terms, we expect that there would be agreement between them and the committee as to whether particular actions should be caught by the code.
"We understand that some members are concerned that a future commissioner may not share such an understanding, and may not consider him or herself as bound by the assurances given when the changes to the code were recommended.
"Those who resist the change consider that, in practice, a committee would not be able to deny consent to an investigation if the commissioner requested it, whatever its views of the merits of the case.
"We do not share these fears, but we recognise there are real concerns."
The committee said it had been "trying to find a compromise which will give colleagues the reassurance they need, while ensuring the principle that allegations about misconduct are investigated by an independent person".
It is now proposing the phrase: "The code applies to members in all aspects of their public life.
"It does not seek to regulate what members do in their purely private and personal lives."
The committee, chaired by Labour MP Kevin Barron, said: "We trust our new proposal will both reassure colleagues that the code will not deal with purely private and personal matters, while reasserting the principle of independent investigation.
"The expectation is that the code and guide will be reviewed once every parliament. There would be nothing but confusion if the current rules were in force after the election, the proposed revisions made shortly thereafter and then replaced by a further revision toward the end of the parliament.
"In practical terms, the changes have to be considered now ...
"If the Government does not find time for a debate, we ourselves will seek a backbench business debate. We would regret this."