Britain's opposition leaders Saturday held their first face-to-face talks on thrashing out a pact to enter government and end the political deadlock left by the general election. Conservative leader David Cameron and Liberal Democrat chief Nick Clegg met alone for 70 minutes to discuss their options on joining forces to oust Prime Minister Gordon Brown's Labour Party from office after 13 years. Spokespersons for the two parties described the talks as 'constructive and amicable', with both sides tight-lipped about the closed-door negotiations. Brown, Cameron and Clegg stood side by side in silence Saturday at a service marking the 65th anniversary of Victory in Europe Day. But despite the show of unity, Britain remained in political limbo with Cameron holding the most seats in parliament but Brown still in nominal power following Thursday's vote. Earlier, some 1,000 protesters staged a noisy rally outside the London venue where Clegg was meeting his lawmakers to consider Cameron's offer to team up. 'It's in the interests of everybody in Britain for us to use this opportunity to usher in a new politics after the discredited politics of the past,' said Clegg, addressing the activists with a megaphone. They were demanding changes to Britain's first-past-the-post voting system to introduce proportional representation, which would help smaller parties like the Lib Dems, the perennial third-place finisher in British elections. The demo was also to urge Clegg not to compromise on the party's commitment to electoral reform in any deal with the Conservatives, who strongly oppose proportional representation. The Conservatives won the most seats in the Thursday's vote but ended up 20 short of an overall majority in the 650-seat House of Commons, leaving Britain with its first hung parliament for 36 years. The Conservatives now have 306 lawmakers, compared to 258 for Labour. The Liberal Democrats dropped back to 57 seats. Northern Irish parties make up the bulk of the rest. With Brown still in the prime minister's Downing Street residence, Conservative and Lib Dem negotiators held a first meeting on Friday and are expected to meet again Sunday morning. The Conservatives want to finalise a power-sharing deal before the financial markets open on Monday, but Clegg will be wary of a hasty agreement that he cannot sell to party members who must give their approval. The parties are not natural bedfellows, with the Lib Dems closer to Labour in many areas. Clegg said they were negotiating in a constructive spirit and making the case for their four key priorities: tax reform, education, the economy and the existing political system. Electoral reform is likely to be the biggest sticking point. In reaching out to the Liberals on Friday, Cameron insisted there was common ground but his suggestion of setting up an all-party inquiry into the issue is likely to fall short of Lib Dem demands. Lib Dem negotiator David Laws said the possibility of an agreement on holding a referendum on proportional representation was one of the matters being discussed, adding: 'We are keen for an early conclusion of these issues.' He said the party's lawmakers had given a 'very clear endorsement' of what Clegg was trying to do, but refused to say if a deal would be done by Monday. A Conservative source also confirmed a deal was unlikely before then. The Conservatives' defence spokesman Liam Fox warned the talks could not be 'held to ransom' by the Lib Dems' proportional representation demands. If a deal cannot be done, Cameron made clear he was also prepared to try to rule as a minority Conservative government relying on support from smaller parties. Brown is waiting in the wings to talk to the Lib Dems if they and the Conservatives cannot force through a deal, and has tried to entice them with the prospect of 'immediate legislation' on electoral reform. The pound slumped to a 13-month low against the dollar on fears the deadlock would hamper Britain's ability to tackle its sky-high public debt. 