Be prepared for the biggest political shake-up since the Great Reform Act

There remains the issue of how constitutional change, welcome though it may be, should be brought about.

Forgive me for quoting myself but I do so only to show how wrong I was. This is what I wrote a few weeks ago in a mood of despair: "Unfortunately political systems are not self-healing. They don't mend themselves. There can be constant deterioration.

"In our lifetimes we have seen no improvement. Only the entry into the House of Commons of new members committed to reform would bring about the necessary change. Is that impossible?" I didn't at the time think that reform-minded members were about to appear in sufficient number to make any difference. I discounted the Liberal Democrats as being too involved in a dysfunctional system.

My underlying fear was that Britain was on the way, in what might be a 20-year journey, to becoming a northern version of Berlusconi's Italy. We would be a country where elections took the form of celebrity contests, where corruption had spread from the original source of infection in the House of Commons and where freedom of speech became harder to sustain.

Shortly afterwards, in this same state of mind, I bumped into Paddy Ashdown, the former leader of the Liberal Democrats. The occasion was a meeting on constitutional reform. The general election had yet to take place. He took my breath away. He responded to my gloom by saying: "Yes, but remember the Great Reform Act. That was when the political class moved sufficiently early to head off what could have been a very nasty situation some years later." Indeed so. We avoided the revolutions that swept through Continental Europe in 1848. As I was leaving, I said to myself that I must remind myself how that was done. I need wonder no longer.

For how extraordinarily prescient Lord Ashdown was. On Wednesday his successor but two, Nick Clegg, now Deputy Prime Minister, claimed that the coalition government's programme of political reform was "the biggest shake-up of our democracy since 1832, when the Great Reform Act redrew the boundaries of British democracy, for the first time extending the franchise beyond the landed classes". The full details of what Mr Clegg meant came on Thursday when the coalition's more detailed agreements were published. Under the heading of defending freedom, I counted a dozen significant proposals. The commitments to repairing our "broken" political system are even more substantial.

I like the conceit of comparing this programme with the Great Reform Act, though there have been at least four occasions in the past 100 years when important changes have been carried through. In 1911, the power of the House of Lords was substantially curtailed and the supremacy of the House of Commons established beyond doubt. In 1918, women were given the vote for the first time with a further act in 1928 completing the process. In 1973, Britain joined the European Union, which resulted in a substantial amount of power being removed from the Palace of Westminster to Brussels. And finally in 1998, Tony Blair's momentous measures to devolve power to Scotland and Wales came into effect.

Of the coalition's constitutional proposals, three groupings deserve special attention. There are those that relate to the voting system. What is planned is not just putting a new system of voting to a referendum, but also the creation of fewer and more equal sized constituencies. In addition there is the novel suggestion that "we will fund 200 all-postal primaries over this Parliament, targeted at seats which have not changed hands for many years". A second highly significant set relates to establishing five-year fixed-term parliaments. The third group that stands out would reverse the recent substantial erosion of civil liberties by means of a Freedom Bill.

The three packages have different dynamics. Voting reform is a big constitutional change and it is rightly subject to a referendum. The campaign will be lively though many people will be indifferent. This is in sharp contrast to establishing a five-year fixed-term parliament that is to be rushed through by placing a binding motion before the House of Commons for approval "in the first days following this agreement". Or at least that is what was said in the first coalition statement; this week's version left out the reference to "the first few days". Reversing the erosion of civil liberties is different again for it is to be achieved mainly by repealing measures put on to the statute book since 1997.

As establishing a five-year fixed-term parliament will come up first, it is the one on which to concentrate. I have no argument with the objective but quite a lot of concern about the means. Its purpose is to remove the prime minister's power to call an election whenever he or she wishes. One can see that this must once have been a valuable part of the royal prerogative. The monarch could ask the very restricted electorate of those days to provide a fresh House of Commons whenever it suited him or her. In due course this prerogative passed to the prime minister of the day, for whom it has had its uses.

Extinguishing this power would mean that there would be no reason for governments to engage in non-stop electioneering from the minute they come into office. Don't forget that the crowds of well-wishers that greeted Tony Blair and his wife Cherie in 1997 when they took possession of No 10 were not what they seemed. There was nothing spontaneous about them. They were party workers instructed to create an impression of unbridled joy for the cameras. At that moment, the next election campaign had already started. That obnoxious practice led to much of the useless legislation, passed only for effect by a supine House of Commons, that is now to be repealed.

Nonetheless, there remains the issue of how constitutional change such as this, welcome though it may be, should be brought about. Most important of all, it should not be rushed. Neither of the coalition partners is going to withdraw any time soon and precipitate an early election. As matters stand, that is inconceivable. So there is plenty of time to get the details right.

I believe the proposal should first be referred to a select committee of the House of Commons. These bodies of MPs have the power to appoint special advisers. They gather written or oral evidence. Ministers may be asked to appear. The cross-examination of witnesses takes place in public. The most appropriate of the select committees to tackle the question of fixed-term parliaments looks to be the Procedures Committee because it considers and makes recommendations on the practices and procedures of the House of Commons itself. It would prepare a report. As a result, Parliament would be able to have a well-informed debate on the floor of the House and approve or not the Government's motion.

The committee would undoubtedly examine and perhaps find a solution to a knotty problem that has already arisen. It is this. If there could be a dissolution during the lifetime of a fixed-term parliament if 55 per cent only or more of the House votes in favour, as the Government proposes, what would happen if the Government began to suffer defeats by a narrow majority of, say, 51 per cent? It would have become powerless yet could still remain in office.

I hope constitutional reform could proceed by such thorough and well-informed procedures as described above. If so, I should begin to think that Mr Clegg's comparisons with the Great Reform Act weren't so far fetched after all. We should be making highly significant improvements in sufficient time.