Rally round the awkward squad in the face of all this spin and control freakery

Tam Dalyell, the backbench Labour MP for Linlithgow, is a maverick – "n, a person of independent or unorthodox views, after Samuel A. Maverick (1803-70), Texan rancher who did not brand his cattle". He is therefore essential to the political health of this Government.

Especially when a prime minister has such an overwhelming majority in the House of Commons, he needs critics on his own side to keep him honest.

Tony Blair once said that John Prescott was like the man employed by Prince Philip of Macedonia, the father of Alexander the Great, to carry a black stick with a pig's bladder on the end and wake him up at night to remind him he was only mortal.

Mr Prescott has long since put his stick down and become a tame adornment of the imperial presidency, but Mr Dalyell still performs this function. As do such robust defenders of the rights of Parliament as Gwyneth Dunwoody, who claims, plausibly enough, that the government machine is still out to get her. The Labour whips tried to depose her as chairman of the Transport Select Committee just after last year's election and were forced to retreat only by the strength of the public outcry.

She and Mr Dalyell must be defended to the hilt. They are a valuable semi-constitutional check on the tendencies of the Government to regard any criticism as a problem to be spun rather than as an argument to be answered. Mr Dalyell is no fan of Mr Blair – ranking him eighth out of the eight prime ministers he has seen in his 40 years as an MP – but he is right to say that no previous Labour prime minister would have tolerated for a moment Jo Moore's lapse of taste on 11 September.

There are signs that Mr Blair recognises that mistakes have been made. His press secretary, Alastair Campbell, says in a letter (opposite) that the Government "must and will learn" from the affair of the e-mail seeking information about the political affiliations of rail safety campaigners.

Yet the instincts of spin and centralising control remain strong. Last month, a conspiracy of the whips – Labour and Conservative – defeated Robin Cook's attempt to free select committees from their malign grip. This is a vital reform, to tip the balance of power in parliament towards select committee chairmen and away from the Government whips, described by Brian Sedgemore, another admirably independent Labour backbencher, as "arm-twisters and goolie-crushers" at the time of the vote to cut lone-parent benefit five years ago.

The complicity of the Conservative whips in defending the privileges of their secret cross-party order somewhat undermines Iain Duncan Smith's attempt to portray himself as fighting for the rights of ordinary people against a power-mad government.

Free-thinking backbenchers are important to the health of our democracy, but they need the platform of committees with real powers of scrutiny and genuine independence to hold the executive branch effectively to account.

Independent-minded committee chairmen do not have to be as abrasive as Ms Dunwoody. Donald Anderson and Chris Mullin have, for example, arguably achieved a great deal more in improving legislation by adopting a more measured approach.

But a government that was confident of its general direction could afford to take a more relaxed view of the awkward squad and recognise that even mavericks sometimes have a contribution to make.