The Government has been rebuked by its own advisers for not clamping down on lobbying by former ministers who take up lucrative private-sector jobs after leaving office.
The watchdog that vets applications by former ministers and civil servants to take other posts within two years of leaving has complained since 2002 about the failure to clarify rules on how they should be allowed to influence legislation and government decisions.
The Advisory Committee on Business Appointments can impose a "cooling off period" such as a year in which former ministers are not allowed to lobby the Government. But it believes such bans are being undermined by the lack of a clear definition of "lobbying".
"There is no simple definition of the term lobbying ... This needs to be rectified," the watchdog said in its annual report, adding that it first raised the "emerging concerns" about former ministers and officials lobbying the Government seven years ago.
The committee said: "It is unfortunate that, in dealing with former ministers, we are still unable to provide them with guidelines which are consistent with the present Ministerial Code." This was issued two years ago.
Lord Wilson of Tillyorn, a former diplomat who chairs the group, urged ministers to bring forward stricter rules as soon as possible.
"Increased levels of concern about the probity of government will undoubtedly affect the way in which the public perceive appointments taken up by former Crown servants and former ministers after they leave government service," he said.
Yesterday the Cabinet Office was unable to explain why it had taken so long to define lobbying. Ministers are expected to respond shortly to a call for a crackdown on outside jobs and lobbying by the Commons Public Administration Select Committee.
In the past year, 12 former ministers consulted the advisory committee about a total of 40 appointments, of which 11 were not taken up.
Those taking up outside posts included the former home secretaries Charles Clarke, who became a consultant to KPMG, and John Reid, who joined G4 Security Services in the same role.