It was the late Harold Wilson who famously remarked that a week is a long time in politics. We have just seen what can be accomplished in a month. Who would have thought that almost four weeks to the minute after he concluded his speech to the Conservative Party Conference, Iain Duncan Smith's successor would have been rapturously received by a packed meeting of Conservative Members of the Commons, Lords and European Parliament after an uncontested election?

In my thirty-three years in the House I have lived through some extraordinary periods but none more so than this. In a matter of four weeks a bitterly divided Opposition that was widely perceived, however unfairly, to be ineffective and incredible as an alternative government, has been replaced by a united party determined to take on the Government with vigour and panache. During the same period rifts have appeared in the Government, and at the highest levels, which a few months ago would have been inconceivable.

I very rarely write in this column about party political issues but I make no apology for doing so this time because I do not think that any reader, whatever his or her political preferences, would deny that an essential feature of a vigorous and successful democracy is an effective and cohesive Opposition, an Opposition that looks as though it could readily become the Government of the day if the electorate decided to entrust it with the task.

I am not saying that the election of a new Conservative leader has totally transformed the political situation at a stroke. The Government will continue to win votes in the House of Commons, almost regardless of the merits of the case, because of its huge majority. Huge majorities do bring their own tensions as we saw when Margaret Thatcher won hers way back in 1983. Prime Ministers with massive majorities, who do not have to worry about whether they will be able to carry their legislation by argument and persuasion, tend to think of themselves as infallible – and that is when the real difficulties can begin. But they can only effectively begin when the Opposition is credible. Mrs Thatcher had no problems when Michael Foot led the Labour Party, and precious few when Neil Kinnock did. But John Major facing John Smith was a different proposition entirely and when Tony Blair became Labour's leader, after John Smith's tragic and untimely death, there was no doubt that the Labour Party was indeed a Government in-waiting. As the Conservative Party turned in upon itself and its Government imploded during the 1992 Parliament, Blair was more and more impressive as an Opposition leader. We all know what happened in 1997. And in 2001 the Conservatives were still not seen either as sufficiently punished, or sufficiently credible, to be entrusted with Government again.

Things have changed since then and I truly believe, for the first time in many years, that we have a realistic chance of winning the next General Election. Michael Howard, as he has said, is bound to make mistakes. The human being who doesn't has not been born. But he look and sounds every inch a party leader, and a party leader, moreover, who could become an impressive Prime Minister. British politics is entering one of the most interesting phases of recent years. I am not a betting man but I would lay a modest wager on a change of occupant in Number 10 sometime between the summer of 2005 and the spring of 2006.

But my wager will not succeed if we do not seize the opportunity to demonstrate that there is a very real difference between the philosophy and the policies of Government and Opposition. Michael Howard was quite right to say that he would lead the Conservative Party from the centre. As the trials and tribulations of the Labour Party in the 1980s demonstrated there is no future for a political party in the United Kingdom if it veers too far to the right or left. But in a system where the centre ground is occupied by the major parties there are real temptations to blur differences and indulge in short-termism – and they are temptations which must be resisted. Let me give just three examples.

There was a perfectly logical case to oppose the war in Iraq. I am one of those who believes most strongly that the Conservative Opposition was right to give total support to the Prime Minister in the crucial debate in March. Nothing that has happened since has changed my mind, for nothing that we have learned has cast any doubt on the evil nature of the Iraqi regime which was overthrown. Those who expected that regime to be overthrown and immediately replaced by a smooth running democracy where the rule of law was implicitly obeyed in every town and village were labouring under a dangerous delusion. The problems that have arisen in Iraq since the fall of Saddam should not make us question the essential rightness of the cause or tempt us to indulge in criticisms that can only serve to help undermine the moral of the forces who are serving us so well and so bravely.

Nor is there any sense in pursuing short-term policies in order to embarrass the Government on the domestic scene. The Government has got itself into all sorts of messes over the reform of the constitution in general and the reform of the House of Lords in particular. But a majority of Conservatives (a small one in the Commons but an overwhelming one in the House of Lords) rejected the thought of a largely elected Second Chamber conscious that such a body would inevitably challenge the supremacy of the Commons and would also replace a house of experts with a house of politicians.

Finally, perhaps the most potentially controversial issue in the Queen's Speech – the funding of Higher Education.

Fundamental to the success of any sophisticated economy in the 21st Century is a vibrant system of Higher Education with institutions which are world leaders. At the moment Britain still has such institutions but those who lead them are unanimous in their view that excellence will become a memory in ten year's time unless they receive significant extra funding. That funding can come from only two sources – taxation or the market. The solution in the offered in the Queen's Speech is far from perfect but we should think long and hard before rejecting it entirely in order to embarrass, or even inflict a defeat on the Government.