New Liberal Democrat leader Nick Clegg has urged other political leaders to work with him to "fix Britain's broken political system".
In a letter posted on the Lib Dem website, Mr Clegg calls on Gordon Brown and David Cameron to cooperate on an independent British Constitutional Convention.
This, he argues, should be tasked with constructing a consensus on the reforms necessary to reopen the political system and revitalise public trust in politics.
Mr Brown highlighted constitutional reform as a personal priority soon after being appointed prime minister this summer and the government is expected to publish its own paper on the governance of Britain early in 2008.
Number 10 sources indicated to the Observer that the prime minister would be willing to discuss constitutional reform with Mr Clegg, even though proportional representation is set to be a key demand of the Liberal Democrats.
Both Mr Brown and Mr Cameron have attempted to court Mr Clegg in the early weeks of his leadership, with the Liberal Democrats set to hold the balance of power in the event of a hung parliament.
Mr Clegg welcomed Mr Brown's early congratulations but made a pointed dig at Mr Cameron's appeal to the Lib Dems to work with the Tories in a "progressive alliance."
He described Mr Cameron's approach as "a little less personal and a bit pre-emptive, but I shall not hold that against him".
Although speculating that the approaches from his main political rivals represented the "latest wheeze by Labour and the Tories to take the best of Lib Dem ideas and call them their own," Mr Clegg said he was willing to work with other parties on constitutional reform.
Setting out his plans for a British Constitutional Convention, Mr Clegg said: "It would examine the role and powers of parliament and ministers; the way in which parliament is elected and held to account; the relationships between the nations of the United Kingdom; the concentration of power in Whitehall; and the need to strengthen basic individual rights and liberties against the abuse of state power."
The convention must be deliberately broad, he argued, to avoid the "pick and mix approach" that has "bedevilled" past attempts at constitutional reform.
Mr Clegg continued: "Fixing Britain's broken politics is no easy task, but it is essential if we are to restore public faith in a system that relies on popular participation.
"Only once we have reformed our constitution to make it open and accessible to every British citizen - regardless of status or income - will we restore public trust and engagement with the policy process."