On the Labour side, senior privy counsellors such as Tony Benn and Peter Shore were being mooted, along with John Morris, the shadow Attorney General.
Membership of the committee would be decided through the 'normal channels' - negotiation between government and opposition whips. But finding suitable Tories without a wide range of outside commercial interests might prove difficult.
Dale Campbell-Savours, the MP for Workington, who has led calls for an investigation, reminded the House yesterday that the Select Committee on Members' Interests ruled in its 1990-91 report that members should withdraw from select committee inquiries where there were conflicts of interest. More arguments might follow about timing in the run-up to the recess. Labour MPs are keen not to lose momentum.
The ultimate aim of some Labour MPs is not so much to ban all outside interests - that is widely viewed as unrealistic; both Labour and Liberal Democrat MPs hold paid directorships and consultancies - but to stop MPs actively pressing issues on their behalf.
Some MPs predict a good half of the current clutch of consultancies and lobbyists would wither away. More cynical Westminster sources warned, however, against expecting too much from the committee. While its remit is unlimited, there is no rule that it must even make a recommendation.
The last Parliament's committee began investigating the leaking of a draft report of the social security select committee report by one of its members, Jerry Hayes, Tory MP for Harlow. Then came the 1992 election, after which no new committee was appointed. The matter ran quietly into the sand.
On other occasions the committee has shown its teeth. Joe Ashton, Labour MP for Bassetlaw, yesterday told the Commons of his experience before the committee in 1974. He had raised the issue of 'MPs for hire' and was censured for contempt of the House even though he was the whistleblower, not a recipient of money.
In 1957, the then editor of the Sunday Express, John Junor, was forced to apologise for a serious contempt at the Bar of the House over an article about petrol allocations to party organisations.
Rulings are not always followed through by MPs, however. In 1986 they voted against the committee's recommendation that Richard Evans, a Times lobby reporter, should be banned from Parliament for six months over the leaking of a draft defence select committee report.