• Clegg wants to lead party ‘well beyond one term’ • Opposes cutting 50p top rate of tax ‘unilaterally’ • Alexander to unveil £500m infrastructure investment • Follow all the latest developments in our live blog Nick Clegg, the Liberal Democrat leader, has insisted he intends to stay at the helm “well beyond one term” amid claims that he did a deal with his wife, Miriam, to step down in 2015 . The deputy prime minister told The Andrew Marr Show that he was in coalition “because I believe it is the right thing to do” as he defended his party’s record in government. Clegg was speaking the day after delivering a combative speech to party’s annual conference in which he sought to assert the “distinctive Liberal Democrat voice” in government as he justified the decision to join forces with the Conservatives – “our political enemies” – in the national interest. Amid fears that the party leadership had become too close to their Conservative coalition colleagues, the Lib Dem leader told delegates on Saturday night that the party was “punching above our weight” in government and doing a “remarkable amount” in delivering Lib Dem priorities. The party had proved wrong those who doubted it was “up to the job” of coalition working, he said in a well received speech. But polling published to coincide with the party’s second autumn conference since joining the coalition suggests the party has failed to convince voters they are a “credible party of government”. Just 24% of the public believe the party is up to the job while only 23% believe they have “done a good job of moderating conservative policies”, according to the ComRes Poll for the Sunday Mirror and Independent on Sunday. Clegg fares the worst of the three major party leaders when it comes to persuading voters what he stands for, with 61% of respondents telling pollsters they “did not know”, compared with 42% who did not know what David Cameron stood for, and 57% who were unsure about Ed Miliband’s priorities.. The poll found 68% of voters believed the Lib Dems would do “much worse” at the next election and just 47% of those who backed the party at the last election would do so again. Overall Lib Dem support has flat-lined at 11%, while Labour have dropped two points to 38% since last month, bringing them level with the Conservatives. In an interview ahead of the second day of conference business, the deputy prime minister set out his pitch as head of a party which he described as having “both head and heart”. But he was also forced to confirm that he intends to stay the course following reports that he had agreed with his wife a timeline for quitting the job. Confronted with the claim of an agreement, made in a book about his rise to high office by journalist Jasper Gerard, Clegg said: “I am in this because I believe it is the right thing to do. Miriam supports me fully in this. And I want to see us succeed in the coalition government and beyond.” Pressed to state his future intentions, he added: “I intend to serve well beyond one term.” Clegg, under pressure to sway doubting party members that the Lib Dems are successfully warding off rightwing policies from the Tory party that would widen inequality and benefit the rich, outlined his party’s determination to face down any move by the chancellor, George Osborne, to scrap the 50p top rate of tax unless it is replaced with another tax on the wealthy. “It stays unless we can first make more progress on lowering the tax burden on people on low and middle incomes, and secondly making sure as the chancellor himself has said we can find other ways the wealthiest can pay their fair share,” said Clegg. Osborne has ordered a review of whether the higher levy is justified by the amount of extra revenue it generates, saying “inefficient” taxes are pointless. Danny Alexander, the Lib Dem chief secretary to the Treasury, will use his conference speech on Sunday lunchtime to announce that a crack team will make sure the richest are paying up. A 100-strong “affluence team” is being drawn from 2,250 newly-recruited tax inspectors expected to be in place within weeks. They will concentrate on the 350,000 people in the UK whose personal wealth is more than £2.5m. Alexander told the Independent on Sunday the move had been “driven forward” by the Lib Dems and would target “particularly people who might be eligible to pay tax at the 50p rate”. Both the Lib Dem leader and business secretary, Vince Cable, signalled on Saturday that the party would only entertain the abolition of the top rate in the long run if it was not raising much revenue and if it was replaced by new taxes on “unearned income”. These could include a 1% annual “mansion tax” on homes worth more than £2m, a land tax, and restricting tax relief on pensions to the basic 20p rate. Clegg told Marr: “I don’t think that it is morally or economically right to unilaterally lower the tax burden on the very wealthy when we haven’t made much more progress as I want us to on lowering tax for the millions of people on ordinary incomes. That remains my principal concern.” Clegg said his party’s “real preoccupation” were the “millions of people in lower or middle incomes”. He said: “They often get overlooked in this debate about what happens to the benefit system at the bottom the wealthiest at the top. The Liberal Democrats are there to really support and be on the side of the millions of people who play by the rules, work hard, pay their taxes and are feeling under an enormous amount of pressure right now.” But he rounded on critics who say the government should slow down its spending cuts agenda: “I think people who advocate that just need to think this through,” he said. “Does anyone seriously think that by ripping up the plan to balance the books that somehow you will create growth by next Tuesday? Actually, it is a complete illusion. What you create is outright market panic, high interest rates and more unemployment.” He said the Liberal Democrat party is “a party of the head and of the heart”, which reflected a balance between social fairness and economic responsibility. “I think if you look at what the country’s been through in the last few years… there are millions of people who want a political party that believes you can create a strong economy and a fair society, and don’t like being told that you have to choose between one and the other. And that’s what the Liberal Democrats are about – we are a party of the head and the heart.” Meanwhile, Cable has pledged to crack down on Britain’s culture of excessive pay for senior executives by signalling moves to make it easier for ordinary shareholders to prevent company bosses being awarded huge sums without delivering exceptional results. In an interview with the Sunday Times, Cable said remuneration had “exploded” and UK firms had a “particular problem”. “The performance of companies has not demonstrably improved, yet people are being paid an awful lot more. There’s something happening that isn’t right,” he said. “You don’t have this problem to anything like the same extent in Scandinavia, Germany, France. It’s a particular feature of our markets. “There is lots of evidence of reward for failure.” Clegg also used his interview to reject any moves to pull back from the European Union. The former MEP called for the British “bulldog confidence” to come to the fore to push for the completion of the single market. “Our absolute overriding priority if we want to protect jobs, if we want to protect communities, if we want to protect families, is to actually deepen and widen that liberal and open free market right on our doorstep,” he said. He said he hoped the eurozone countries would “get their act together” and make it a success, adding: “The last thing we should do is say ‘oh in that case we wash our hands of the whole enterprise and we’ll get out’. That will destroy jobs and destroy prosperity in this country.” Asked if the government should slow down the cuts programme, Clegg said: “I think people who advocate that just need to think this through. “Does anyone seriously think that by ripping up the plan to balance the books that somehow you will create growth by next Tuesday? Actually, it is a complete illusion. What you create is outright market panic, high interest rates and more unemployment.” Liberal Democrat conference 2011 Liberal Democrat conference Liberal Democrats Nick Clegg Income tax Tax Liberal-Conservative coalition Danny Alexander Hélène Mulholland guardian.co.uk