LONDON: The three main political parties contesting Britain’s election on May 6 are facing increasing scrutiny of their spending plans and have been accused by one of the nation’s most respected economic think tanks of fudging on the scale of planned cuts.As the Labour Prime Minister, Gordon Brown, the Conservative leader, David Cameron, and the new star on the political stage, the Liberal Democrat leader, Nick Clegg, prepare for tonight’s final television debate on the economy, all three have been excoriated by the Institute for Fiscal Studies, an influential independent policy body.The public has been well prepared for a period of austerity but, says the institute, which prepared an analysis of the three parties’ plans to slash Britain’s £163 billion ($271 billion) deficit, the real pain has not been properly explained.The institute described as ”vague” the three parties’ plans to slash between £30 billion and £40 billion from the budget in the coming year and said none had gone ”anywhere near” what will be needed to meet its debt reduction pledges and timetables.Each party has promised cuts that reflect its own philosophical bent, with Labour protecting front-line services – nurses, police and teachers – and proposing a rise in national insurance tax rise to plug the hole and the Conservatives proposing cuts in public service ”waste” to ensure no tax rises. The Liberal Democrats have promised big cuts of £47 billion, but only 23 per cent have so far been identified.Anxiety about Britain’s economic future was highlighted as news spread that Greece’s credit rating had been ”junked” by the international agency Standard & Poors. The London sharemarket suffered its biggest drop since the beginning of the year.The rising sense of financial and political uncertainty was reflected in reports in the Financial Times that the Conservatives were exploring a deal with Unionist politicians in Northern Ireland and with Welsh nationalists in an effort to avoid Liberal Democrat demands for electoral reform.Senior Conservatives are bitterly against moves to change the first-past-the-post voting system for some form of proportional representation, which they fear would entrench smaller parties such as the Liberal Democrats.Mr Clegg was enjoying a second week of strong opinion polls, and on Tuesday finally caught the attention of conservative newspapers, which had studiously ignored his party.In an interview with The Times, Mr Clegg said that he harboured the notion of becoming prime minister and that his party had stolen the mantle of the progressive centre left from Labour.”I think we have won the progressive argument in this election. Of course, not in terms of numbers of seats, and we’ll see on May 6 whether it’s numbers of votes. But intellectually, the assertion that the progressive cause is a Liberal one, not a statist Labour one.”The big choice, he told The Times, is between ”two competing pitches for change”: the Conservatives and the Liberal Democrats. ”I think more … people in the Labour Party are coming to appreciate that. That’s why the big choice now, if not psephologically but intellectually, this is now a two-horse race between the Conservative Party and the Lib Dems.”