Leading article: The hard lesson for Labour's new MPs: Speak your min ds

It's embarrassing. Here we are, stern critics of the ermine-clad brigade sitting there unelected in the House of Lords, applauding their courage and perspicuity. First it was the revolt of the Labour peers, joining cross-benchers and a smattering of brave Tories to vote for amendments to the Competition Bill to allow proper testing of Rupert Murdoch's pricing policies. Now it's the decision by the Lords' Science and Technology Committee to set up an inquiry into the case for decriminalising cannabis.

Led by the former vice-chancellor of the Open University, Lord Perry of Walton, a group of peers is to look dispassionately at the drug and the contexts in which it is used. Far be it from us to anticipate the outcome. Suffice it to say that a lot of other distinguished people have, on examining the arguments and consulting their own experience, concluded that the law as it stands is not only ineffective but unsound. To judge by the track record of the Science and Technology Committee, as of other specialist investigations by the peers, there is every reason to expect Lord Perry's team to respond to the weight of argument and evidence and reach pretty much the same conclusions as the Independent on Sunday has lately been campaigning for.

Of course that does not alter any fundamentals about the Lords. A modern democracy has no need of the hereditary principle and ought to look with suspicion on government by appointees. What we have witnessed this week is action by a small group of liberal-minded peers, who know that ultimately what they do and say stands to be countermanded and contradicted by the Government and its supporters in the House of Commons. The House of Lords, moreover, still contains many silent, whipped government placepeople, those sit-on-their-hands Tories, purposeless Anglican bishops, not to mention coachloads of hereditary landowners and peers-by-descent, who turn up only to collect their attendance allowances and when they do speak sound as if 1832 were but yesterday.

It won't do to say that lordly liberalism in itself makes a case for dividing lawmaking into two segments, granting powers to an older, wiser second chamber, in order to revise or challenge the decisions of the principal legislature. It is plain that the peers have been made to look good only because the House of Commons lately has looked so supine. The problem is partly that of the historical condition of the Tories - defeated, unimaginatively- led and (still) fatally riven on Europe. They resort to character assassination in place of policy development, quibbling in place of the sustained assault that Labour's plans for Britain deserve (not because they are flawed, but because they will be better thanks to criticism).

But the problem is more Labour's hegemony and the way the Blairite project seems to have reduced MPs to mere automata. It is a paradox. With that huge majority in the Commons, MPs - one might think - could relax a bit, exercise their cerebella, let fly an occasionally radical thought. Instead the whips patrol the corridors like warders around an Alabama chain-gang. Labour MPs cry into their beer and bemoan their fate - but totally off the record, old chap.

Sometimes, however, there are glimmerings. The anti-Murdoch forces in the Commons are mustering, their ranks said to include even such proto- New Labourites as Giles Radice, fighting the revisionist fight (as one commentator put it) while Tony Blair was still in nappies. Yesterday Margaret Hodge, till now loyal in thought word and deed, sank her teeth into the flesh of Chief Inspector Chris Woodhead, despite the entree he enjoys at No 10. Whether Mrs Hodge's committee is right to single out Ofsted in this way is not the issue: this kind of work is what backbench specialists are supposed to do.

Is this evidence that the worms are beginning to turn? No one is advocating parliamentary anarchy nor the abandonment of party discipline in pursuit of the Blair government's central goals. No one is saying that executive government can be effective without being able to rely on guaranteed support in the lobbies. But none of that means they cannot challenge ministers and their prejudices, especially on issues which are far from central to this Government's existence.

Labour MPs should have asked more searching questions about the purposes of British armed forces in the Gulf. They have every right to ask Mr Blair just why preserving the friendship of Rupert Murdoch is so necessary. It is open to them to quiz Mr Straw on his unargued hard line on soft drugs. If the old men in the Lords can do it, why not the younger men and women in the Commons?