The Committee on Standards in Public Life is pressing ahead with plans to examine the conduct of MPs, and has announced a new inquiry into the use of special advisers by ministers.

It comes amid claims that some special advisers have bullied full-time civil servants into carrying out overtly political attacks on Labour's opponents.

Jo Moore, a special adviser at the Department of Transport, Local Government and the Regions, is said to have pressurised civil service colleagues to conduct a smear campaign against the London transport commissioner, Bob Kiley.

She also stands accused of seeking to secure a key civil service post for a former colleague.

The committee, chaired by Sir Nigel Wicks, had previously announced its plans to examine the operation of the independent parliamentary commissioner for standards in the wake of the row over the decision not to re-appoint Elizabeth Filkin to the post.

But in a move that will add to the discomfort of a government repeatedly attacked for its use of "spin", the Wicks committee is also set to investigate the boundaries and relationships between ministers, special advisers and permanent civil servants.

The committee will publish a consultation paper on standards in the Commons on February 25, marking the first stage of the formal process of inquiry. Written submissions will be sought on the issues raised in the consultation paper, and these will be followed by public hearings.

A consultation paper on issues surrounding the use of special advisers will be published on March 4, with the two inquiries anticipated to run side by side for most of 2002.

"The enquiry will focus on the boundaries and relationships between the three different parts of the executive. It will consider the delineation of those boundaries and compliance with them," said Wicks.

The theme of the investigation will be that ministers, permanent civil servants and special advisers are all holders of public office and that therefore the sevenprinciples of public life apply to them.

"The committee's timetable over the next few months will be determined to some extent by the amount of written evidence we receive. But on each topic we will follow our usual methodology, which will include a series of public hearings, consideration of all submissions and publication of conclusions and recommendations, along with all the evidence, in due course," said Wicks.