The Prime Minister is preparing to publish the report of the committee - set up to study the conduct of MPs in the wake of the "cash for questions" scandal - within three weeks, and act on its recommendations.
One hundred and sixty-three MPs declare one or more consultancies in the Register of Members' Interests, and a large number of these are "advocacy" consultancies, requiring them to use the proceedings of parliament in the interests of their clients. The Nolan Committee is expected to bear down heavily on these lucrative consultancies, which have mushroomed in recent years. Some MPs have half a dozen or more. The record is thought to be held by David Mellor MP, the former heritage secretary, who lists 11.
Nolan is expected to draw a distinction between "advocacy" consultancies, which rely on access to ministers and civil servants and the use of parliamentary questions and debates in the House, and "advisory" consultancies, that simply keep a client up to date on developments. Advocacy consultancies will be banned or tightly regulated. MPs will also be forbidden to sit on the boards of lobbying companies
Mr David Riddick, the Conservative MP for Colne Valley who was last week suspended from the Commons for 10 days over the "cash for questions" scandal, was paid £12,000 a year to act as a consultant to the Brewers' Society. He resigned from the post last August after the Sunday Times disclosed that he had agreed to table a parliamentary question in return for £1,000 from a reporter posing as a businessman. Mr Riddick argued that he was led to believe that a consultancy was being created, which is within the rules.
The Commons Privileges Committee, which recommended his suspension, said: "We see no sustainable distinction between a payment of £1,000 for tabling a parliamentary question and a consultancy for which the fee is £1,000 and the only requirement the tabling of a parliamentary question."
Dale Campbell-Savours, Labour MP for Workington and scourge of Westminster's "double-jobbers", said yesterday: "The days of consultancies which are dependent on parliamentary proceedings are numbered."
The Nolan report will also recommend wide-ranging reforms in the appointment of people to quangos, greater parliamentary oversight of MPs, an "Ethics Advisory Office" for the Commons and a ban on the "revolving door" practice that allows ministers to take jobs with firms that they have privatised.
MPs dissatisfied with the limited scope of the committee's investigation say they will use the Nolan report to reopen the issue of consultancies and MPs' outside interests. David Alton MP, a Liberal Democrat critic, said: "The umbilical cord between consultancies and being an MP should be severed. It is impossible to reconcile the role of a member of parliament, who should be pursuing causes, following his conscience and looking after the constituents' interests, with the work that being a consultant advocate entails."