Today Jack Straw is expected to announce a new amendment to the Constitutional Reform Bill that would allow life peers to renounce their peerages. There is one life peer who might well benefit from this opportunity. This is Peter Mandelson, who is probably the most powerful minister in the present Cabinet. For him, this would open the opportunity to return to the House of Commons, an option that would increase his political strength whether he ever took advantage of it or not.

In the House of Lords, Lord Mandelson is a powerful minister, with an unusually wide portfolio, but he can never become Prime Minister or leader of the Labour Party. If this legislation is carried, he will be free to go back to the Commons and would therefore be potentially available as the leader of a party that is now very close to collapse.

Most peers have enjoyed having Lord Mandelson on the government front bench in their House. He answers questions with the glossy skill of a Victorian top hat. He is to be seen working the lobbies, stopping for a word here, greeting a couple of his friends, making a flattering comment or a subtle correction. British politics has seen nothing quite like it since Talleyrand last walked up the steps of the Travellers Club. It seemed a master stroke of Gordon Brown’s to have brought him back from Brussels last year, but who is the master now?

The latest public opinion polls suggest that the Government may be in terminal decline. There were two published yesterday. On its record, I tend to follow YouGov, which appeared in yesterday’s Sunday Times. Its figures are: Conservatives 42 per cent, Labour 25, Liberal Democrats 18. The Independent on Sunday published a ComRes survey, which puts the Conservatives on 38 per cent, Labour on 23 and the Lib Dems on 22.

From the Labour point of view, the ComRes poll is the more alarming. People are already beginning to wonder whether Labour will ever again be able to form a government on its own, or whether it is in a decline similar to that of the old Liberal Party in the 1920s. These are only immediate polling figures, but they follow Labour’s May disasters in the local government and European elections. On Thursday there will be the Norwich North by-election; Labour needs to hold its seat but is not expected to do so; even the Greens are a threat.

Peter Mandelson’s comeback did not start in the House of Lords; it started in Brussels, where he proved an effective Commissioner in trade negotiations. He should not be seen as a mere careerist, though he may well want to achieve his grandfather’s frustrated ambition of leading the Labour Party to an election victory. His grandfather was Herbert Morrison, the Home Secretary in Winston Churchill’s wartime coalition.

One can trace his consistent personal loyalties, which may give a clue to his likely strategy in the next nine months. He is loyal to the Labour Party, loyal to the European idea and personally loyal to Tony Blair. He was not loyal to Gordon Brown when he had to make the choice between Brown and Blair. He is loyal to the new Labour idea and was an important architect of new Labour’s victory in the 1997 general election. These loyalties are likely to decide his policies in the run-up to the next election.

I have no doubt that Lord Mandelson genuinely desires a Labour victory at the next election; so, of course, do most Labour politicians. I believe he is one of the few who believes that such a victory is possible. In his own words after the 2001 general election, he is “not a quitter”.

His first objective has been to keep the Labour Party afloat until the Lisbon treaty has been ratified. He is hoping that the Irish will vote “yes” in their referendum, probably in early October. That would create an opening for Tony Blair to be appointed president of Europe, which may be the second stage of the strategy.

If the Conservatives win the next election before the Lisbon treaty has been fully ratified, they plan to call a referendum, which would presumably reverse the existing ratification. If the Conservatives are in office before the new president of Europe has been elected, they will not support Tony Blair.

If the Lisbon treaty ratification and the Blair presidency should both be successfully achieved by Christmas, the Labour Party would still face a difficult election next year. However, Lord Mandelson would need to leave the House of Lords in something of a hurry. If he were to fight a Commons seat in a May election, that might be enough to make him a potential leader of a new Blairite Labour Party.

Labour cannot expect to win the election under the leadership of Gordon Brown. But an election fought with Tony Blair as the European president and Peter Mandelson as a candidate for the Labour leadership might be another matter. There is, after all, no obvious alternative leader, except Harriet Harman.

New Labour, which won three general elections, was largely created by Mr Blair and Mr Mandelson. A pro-European campaign, led by the two of them, would open a serious contest for the centre ground, squeeze the Lib Dems and fight back strongly against the Tories.

Obviously, this would be a vulnerable strategy, as fragile as a Ming vase. Lord Mandelson himself may not regard it as feasible. It may be too late: Lisbon may not be ratified; Blair may never become president. The public distaste for the memory of the earlier Blair- Mandelson years may be too great.

Nevertheless, Jack Straw, presumably with the consent of Gordon Brown, has decided to let the leopard out of its cage. The leopard has not changed its spots; if released, it will seek its prey, which is power. Perhaps it would be safer for all concerned if the cage were kept firmly shut.

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