Sixsmith banned from testifying to spin inquiry

Martin Sixsmith, the former press chief of Stephen Byers, has been banned by the Government from giving evidence to a high-level inquiry into the role of special advisers.

The former civil servant, whose dispute with Jo Moore, Mr Byers' spin doctor, prompted the resignation of the former secretary of state, has been warned not to give evidence before the powerful public standards watchdog. Mr Sixsmith was asked to testify by the Committee on Standards in Public Life, which begins an inquiry today into the role of ministers' special advisers.

Sir Nigel Wicks, who is the chairman of the committee, is believed to have asked the Government whether Mr Sixsmith, a former civil servant, could give evidence. He is said to have been keen to appear before the panel and give his insights into the innermost workings of government, such as the relationship between civil servants and advisers.

But the former communications chief, who was asked to sign a gagging order after leaving his post at the Ministry of Transport, was warned in stark terms not to give evidence to the committee. Downing Street and the Deputy Prime Minister's Office have been in discussions with the Wicks Committee on who should give evidence.

Mr Sixsmith's dispute with Jo Moore is said to have been a main factor in prompting the inquiry, which will look at whether there are sufficient curbs on special advisers. Sir Nigel is concerned at the growing number of special advisers and is expected to look into whether they have been putting pressure on civil servants to act "politically."

The ban on the former civil servant is believed to relate to the Government's insistence that Mr Sixsmith, who was forced to resign by Stephen Byers, should not talk publicly about his time at the ministry. He has yet to receive a £180,000 pay-off as the Government seeks new guarantees that he will not reveal any information on his time in Whitehall.

The ban is likely to be seized on as proof of "control freakery" by the Government, which has been keen to draw a line under the Stephen Byers affair.

Jo Moore and Alastair Campbell have also been invited to give evidence.