Select committee chairs could be banned from holding outside interests following the Tim Yeo scandal, after parliament and government figures indicated their willingness to change the rules quickly.
Speaker John Bercow has written to Kevin Barron, the chair of the Commons' standards committee, asking him to investigate the issue because he believes "there is a reputational issue for the House involved".
Yeo stood down from his position as chair of the energy and climate change committee after a Sunday Times sting caught him offering to put an energy firm in touch with influential figures, including those within government, in return for cash.
The scandal has prompted calls for reform of the system and Bercow has now revealed he has been considering the matter for some time.
"Last November, I mentioned to the Government chief whip and the parliamentary commissioner for standards my concern, on behalf of the House, about what many might regard as an inherent incompatibility between chairing a select committee and having commercial interests, even though fully transparently registered, in the sector covered by that committee," the Speaker wrote.
Yeo has registered interests worth over £100,000 a year from the energy sector.
He had defended his financial interests to Politics.co.uk as recently as last week, saying in an interview: "I think it's quite hard for anyone to sustain the argument what I'm doing is the result of financial interests.
"My judgements... are better-informed because I talk to people in business more than I otherwise would."
Now Bercow has asked Barron's committee to probe the issue and make a recommendation to the House.
"Colleagues would then have the opportunity to decide whether to maintain the status quo, or to introduce a new rule on the subject," he suggested.
Select committee chairs are coming under more scrutiny since becoming directly elected by MPs.
Conservative select committee chairs Richard Ottaway and John Whittingdale both defended the current system in a Times newspaper article this morning.
Ottaway earns additional income as a solicitor and arbitrator, while Whittingdale is a non-executive director of an online music cataloguing firm.
The majority of select committee chairs do not receive significant income from sources outside parliament, however. Ironically, only Sir Robert Smith - the Liberal Democrat appointed interim chair of the energy committee - would be adversely affected.
He holds registrable shareholdings in an integrated oil company worth at least £66,000.
Leader of the House Andrew Lansley has already signalled the government's willingness to allow Commons time to debate the changes, which the coalition would not oppose.