Labour accuses Dave Cameron on 50p tax rate Mr Cameron told MPs that the effect of a Labour amendment opposing the 45p rate, to be voted on in the Commons later today, would be to leave those earning over £150,000 paying the even lower 40p rate. But aides of Labour leader Ed Miliband said this was untrue, telling reporters: "He knows you can't use budget votes to bring in a new tax rate. It's completely out of order. The row blew up following fiery exchanges at Prime Minister's Questions in the Commons, during which Mr Miliband branded the Budget an "omnishambles" which had conned pensioners and made charities, churches and pasty-eaters worse off. But the Prime Minister defended Chancellor George Osborne's package, telling Mr Miliband: "This Budget cut taxes for 24 million people, this Budget cut corporation tax, this Budget made Britain competitive." And Mr Cameron called on the Labour leader to withdraw his income tax amendment, warning: "If he is successful, he will give us a 40p tax rate." Mr Miliband said Mr Cameron was "talking rubbish as usual," and aides later said that Mr Cameron must be aware that the Labour amendment would not restore the 40p rate, but leave the top rate "undecided," forcing Mr Osborne to come back with fresh proposals. "We are angry at Cameron's claim that we could have used a budget vote to bring back the 50p rate," said a senior Labour source. The clear advice from Commons clerks is that it has always been out of order to use budget votes to bring back a rate of tax. But a source close to Mr Cameron responded: "Labour have bungled their amendment, as clear as day, and they should just accept that and rephrase it or pull it." While many Conservative backbenchers are known to be keen to see a return to the 40p rate for top taxpayers, the source said there would be a three-line whip on them to oppose the Labour amendment this evening. MPs will vote later today not only on the 50p rate, but also on a bid by rebel Tory and Liberal Democrat MPs to derail the introduction of 20% VAT on hot food like Cornish pasties. The votes come on the day an influential Commons committee released a critical report on the Budget. The Treasury Select Committee said the figures used by Mr Osborne to justify axing the 50p rate were "highly uncertain" and suggested that ministers had failed to make the case for capping tax relief on charitable donations. The committee also called for action to protect pensioners, who have seen the value of their savings hit by the Bank of England's decision to print money through quantitative easing. After weeks of criticisms directed at different aspects of Mr Osborne's package, Mr Miliband said it was clear that the Budget had "comprehensively failed the test of fairness and spectacularly failed the test of competence." Branding Mr Osborne a "part-time Chancellor," the Labour leader said that the Budget would deprive charities of £500 million in contributions and hand over at least £40,000 a year to millionaires. He said that Mr Cameron was "a desperate Prime Minister who can't even justify his own Budget." Appearing before MPs for the first time since the March 21 Budget, Mr Cameron accepted he had had "a tough month." But he insisted: "What this Budget is about is actually cutting taxes for 24 million working people, taking two million people out of tax, freezing the council tax, cutting corporation tax so we are competitive with the rest of the world. And for pensioners, we've increased the basic state pension this month by £5.30 a week. Far more than Labour ever would have done so. He called on the Labour leader to condemn the "disgraceful" tax arrangements of his party's candidate for London mayor, which he said would see Ken Livingstone pay less tax than cleaners at City Hall. He mocked Mr Miliband over Labour's loss of the Bradford West by-election to Respect's George Galloway - who used his first PMQs since returning to Parliament to demand the withdrawal of UK troops from Afghanistan. As MPs prepared to vote on the 50p rate, today's Treasury Committee report warned: "The cost and benefits of reducing the additional tax rate to 45p are both highly uncertain, and could be significantly more or less than the cost included in the Budget. Labour later released advice from the Commons clerks' office which confirmed that, if passed, their amendment would leave the top rate of income tax for 2013/14 "undecided" rather than reducing it to 40p. Liberal Democrat economic spokesman Stephen Williams said: "It is worrying that the two Eds don't understand the fundamental principles of our tax system, despite having worked in the Treasury for many years as Gordon Brown's backroom boys. It took them 13 years to introduce a 50p rate and then they only did so shortly before a general election. Now that the local elections are coming up, suddenly they care about it again and put down ill thought-through amendments that remove the top rate altogether. Labour's biggest tax change was to remove the 10p tax rate, hitting people on low and middle incomes while Liberal Democrats are giving nearly 25 million basic-rate taxpayers an income tax cut and have lifted more than a million people out of paying income tax altogether. At the same time, we're making the rich pay their fair share by cracking down on loopholes and excessive tax relief.