Robin Cook, Labour's policy supremo, and Robert Maclennan, president of the Liberal Democrats, jointly announced that work had begun to work out the details of reforms, above all on a referendum to change the voting system for the House of Commons. Despite Mr Cook's insistence that "this is not a pact", and Mr Maclennan's declaration that it was a "ringfenced" agreement, restricted to constitutional changes, the meeting clearly marks one of the most important steps in the rapprochement between the two main opposition parties.
Mr Cook and Mr Maclennan have held one-to-one talks, sanctioned by Tony Blair and Paddy Ashdown, for over a year. But yesterday they were joined by senior colleagues in a formal committee to find "common ground" in plans for a Scottish parliament, Welsh assembly, a London authority, a referendum on electoral reform, a Freedom of Information Act and reform of the House of Lords.
On Labour's side, the meeting was attended by Donald Dewar, the chief whip, Ann Taylor, shadow leader of the House, George Robertson, the Scottish- affairs spokesman, and Jack Straw, under whom the Home Office would be the lead department for many of the reforms. At future meetings they will be joined by Ron Davies, Welsh-affairs spokesman, and Lord Richard, Labour leader in the House of Lords.
For the Liberal Democrats, Mr Maclennan was joined by Jim Wallace, leader of the Scottish National Party, Nick Harvey, MP for North Devon, and Lord McNally, who as Tom McNally had personal experience of a Labour government, working for James Callaghan.
"The Labour Party and the Liberal Democrats will fight the next election as distinct parties with separate candidates in every constituency," Mr Cook said at a Westminster news conference. "Nor is this the start of some grand new realignment of British politics."
Yesterday's development follows signs that Mr Blair and Mr Ashdown have developed a close working relationship. Both have hinted at a dramatic realignment of politics after the next election, including some one-nation, pro-European Conservative MPs.
"We are confident that there will be a majority for reform in the next parliament," Mr Cook said yesterday.
And Mr Maclennan pointed to the lessons of Harold Wilson's 1966 government, which, with a Commons majority of 100, failed to push through its reforms of the House of Lords.