Budget negotiations go to wire as Clegg and Cameron fail to agree David Cameron and Nick Clegg are still negotiating over next week's budget. David Cameron and Nick Clegg are to take their negotiations on next week's budget down to the wire after they failed to reach agreement at a meeting of the "quad" group of senior ministers on Monday. As Ed Miliband ratcheted up the pressure on the coalition by calling on George Osborne to "ease the squeeze" on families by reversing cuts to tax credits, senior ministers agreed to hold another meeting of the "quad" next Monday. Cameron and Osborne, who fly to Washington on Tuesday for a three-day visit to the US, are due to hold a telephone "quad" discussion with Clegg and Danny Alexander, the chief secretary to the Treasury, on their return to Britain on Friday. The ministers will then hold their final meeting on Monday, 48 hours before the chancellor delivers his third budget. The prime minister and chancellor were irritated with the Lib Dems after they outlined some of the budget thinking at their spring conference in Gateshead. Clegg announced his support for a "tycoon tax" which would ensure that millionaires pay a minimum amount of tax, around 30% on all their income. It is understood that Osborne may announce a study into the feasibility of such a tax. Clegg also made clear that he wanted an accelerated move by the chancellor to deliver the coalition commitment to raise the income tax threshold to £10,000 to ensure that low-paid workers are exempt from paying tax. The allowance is due to increase by £630 a year to ensure the £10,000 target is met by April 2015. Senior Lib Dems said over the weekend they would like the target to be met a year earlier. The deputy prime minister clashed with the business secretary, Vince Cable, by appearing to indicate that the "tycoon tax" was a greater priority than a "mansion tax" that would be levied on properties worth more than £2m. Lib Dem sources also indicated that they were relaxed about dropping the 50p tax rate on those earning more than £150,000 if Osborne agreed to speed up moves on the £10,000 tax allowance. The wrangling in the coalition came as Ed Miliband accused the government of being out of touch by spending the past few weeks "arguing about the political cover they need" to cut the 50p top rate of tax for those earning above £150,000 while families' living standards were squeezed. He cited figures that suggested the average family would be £530 worse off on average from next April while top earners had received a tax cut worth £1.6bn since 2010. Miliband said cutting the top rate of tax was the wrong priority and the focus should be on reinstating working tax credits for up to 200,000 working couples "trying to do the right thing." The Labour leader highlighted plans which could almost halve the rate of pensions tax relief on top earners and allow the government to reverse cuts to working and child tax credits. Miliband was flanked by his shadow chancellor, Ed Balls, who said the previous Labour government had cut the tax relief on pension contributions available to high earners when it introduced the 50p top rate of income tax. This meant that anyone earning more than £150,000 would only be able to claim relief at 20%, raising £4bn. Based on the House of Commons research, and taking into account the changes to the pension cap that George Osborne has already introduced, a reduction in the rate at which top-rate taxpayers can claim pensions tax relief from 50% to 26% would be sufficient to reverse this tax cut - with the funds raised then available to help those on low and middle incomes. Balls said Labour would support a wealth tax such as the mansion tax favoured by Cable, and he had offered to work with Osborne to "get the details right." But he said the priority for the revenue raised from such a tax would be to help low- and middle-income earners being affected by rising petrol prices, energy bills and taxes. Miliband said next week's budget was set against a backdrop of the highest unemployment for 17 years, stagnant growth and living standards facing an unprecedented squeeze, suggesting that the economy was not working. The cuts that tell working people it's not worth working, that tell working women affordable childcare is out of reach and that tell working families: 'You're on your own.'