After six long years, the Tories have rediscovered the art of opposition

We may be at the point when the public begins the steady march from grumpy, unenthusiastic support for Blair to outright hostility

It is said that, for several centuries after the fall of the Romans, the art of making cement was lost. Since 1997, according to Margaret Thatcher's former Downing Street political secretary, Stephen Sherbourne, the Conservatives appear to have lost the art of being in opposition. This is partly because they were in denial, he says. Too many believed that they were the natural party of government and could not cope seeing members of another party being chauffeur-driven in government cars and carrying ministerial red boxes.

For the past few days, however, the Tories seem to have rediscovered the lost art of political cement manufacturing, and they have given the impression that they are an opposition worthy of the name. Last week's devastating critique by the shadow Chancellor, Michael Howard, of the Government's continued fence-sitting on the euro, has shown the rest of the Tory front bench how to land punches. Many others in the Shadow Cabinet have been piling into the opportunities created by the Prime Minister's shambolic handing of the recent ministerial reshuffle.

The Tories have successfully got over the message that the constitution is not the plaything of the Prime Minister. Iain Duncan Smith made the running when he drew attention to the unilateral nature of the announcement to abolish the post of lord chancellor without any prior consultation, White Paper, debate or vote in Parliament.

The chaotic nature of the arrangements relating to Scotland and Wales, with Lord Falconer of Thoroton nominally in charge of "constitutional affairs", and Peter Hain and Alistair Darling answering in the Commons while doing other full-time cabinet duties, offers many opportunities to a competent opposition for more than just mischief making. As if to underline the point, yesterday, when Mr Darling should have been concentrating on sorting out the rail chaos, there he was moonlighting because he was required to appear before the Scottish Affairs Select Committee.

The Tories are right to make much of the insult to Parliament, and - devolution notwithstanding - to the people of Wales and Scotland. Mr Blair cannot be allowed to toss around great offices of state among his cronies like old cloaks. The insult is underlined when, in the same reshuffle, Alan Milburn left the Government precisely because the demands of a single office were too great to manage alongside a normal family life. Tories are also right to be outraged by the decision to appoint a Scottish MP to the English health portfolio.

I recall, during my time in Parliament, Robin Cook making it clear, when he was shadow health spokesman - but representing a Scottish constituency - that should devolution occur, he could not serve as a health minister responsible solely for England. His words should be repeated by every Tory MP, as Eric Forth did yesterday, whenever John Reid rises to answer Commons debates or questions.

The intervention of the Speaker, Michael Martin, in response to the Tories' demands for the Prime Minister to give an account of himself is to be commended. Over the past three years, for all the brickbats and petty insults he has endured, Mr Martin is turning out to be a much under-estimated figure. By showing Mr Blair the red card, he has become the principal guarantor of the rights of the Commons.

As a result, Mr Blair will be required to make a statement later today and submit himself to Commons scrutiny. There are few formal powers given to the Speaker to demand the attendance of ministers to answer questions and debates. Exhortation, hitherto, has been the only weapon available, but Mr Martin has set a bold precedent by his decision to tell Downing Street in no uncertain terms that the Prime Minister has serious questions to answer from Mr Duncan Smith and other MPs.

It was a disgrace that the Prime Minister did not attend the Commons yesterday for the opposition debate on the shambles, but his absence enabled Mr Forth, who led for the Opposition, to make a mockery of the ministerial changes by continually referring to Peter Hain, who replied instead of Mr Blair for the Government, as the "part-time Leader of the House". Mr Forth demonstrated the old fashioned assets of a good Commons performer. This enabled the Tory backbenchers to unite around a simple mantra: that this is a government that has no regard for the constitution, fails to deliver on its public service promises and is perceived as untrustworthy and dishonest.

Of course, parliamentary shenanigans over which minister does what job, and what title they are called, cut little ice outside the Westminster village. Few will be losing sleep over whether Lord Falconer is called lord chancellor or secretary of state for constitutional affairs. Not many in the pubs will have been discussing the proposed arrangements surrounding the appointment of judges or whether there should be a Supreme Court.

But a reshuffle is normally used to indicate to the general public that the government is being refreshed and has a renewed sense of direction.

Because the reshuffle has failed, the Prime Minister had to re-state those objectives, yesterday, in his speech to the Fabian Society. There is a growing public perception of failure to deliver. This is why the mood of untrustworthiness, which began to appear after the failure to find weapons of mass destruction in Iraq, is now in danger of taking root on the domestic policy front. The latest opinion poll, which shows Labour just four points ahead of the Tories, underlines that lack of trust has become the central problem for the Government. And yesterday's appearance of Robin Cook and Clare Short before the Foreign Affairs Select Committee will have added to this perception.

In previous crises over policy delivery, Mr Blair was able to pull the levers marked "relaunch" by promising more resources for the public services. Now, the lack of financial resources is no longer available as an excuse for failure. Taxes are rising inexorably and no one can deny the vast sums of public expenditure which are currently being poured into health, transport and education - all to little outward avail.

Mr Blair's Fabian speech merely reiterated his now familiar message of more reform, but it was received with little enthusiasm from the public services union Unison - and even less from the disgruntled ranks of Labour MPs. There is now the serious prospect of industrial action looming over the NHS and the danger is that Mr Blair has used up his remaining credibility. To drive further reform of the public sector he will require exceptional trade union co-operation - which appears to be evaporating as each pro-Blair union general secretary is replaced.

We may just be at the "tipping point" when the public begins the steady march from grumpy, unenthusiastic support for Mr Blair to outright hostility. When that happens the Tories need to be ready. This week, at least, they momentarily looked like a government in waiting.

mrbrown@pimlico.freeserve.co.uk