The IMF says plans to reduce government debt are holding the economy back. It's the most forthright criticism yet of Osborne's austerity.
Alex Salmond, has set about trying to reverse the impression that a vote for independence next year will hit the Scottish economy.
David Cameron sent an email to members of his Conservative Party urging unity.
Prime Minister David Cameron said an EU deal to move towards full cross-border disclosure of tax information will give momentum to a G8 summit he will host next month in Northern Ireland on the same subject.
Talks in Brussels today claim to have removed obstruction by Luxembourg and Austria.
Both countries had previously prided themselves on their banking secrecy.
He said: "Tax evasion and aggressive tax avoidance are at the heart of the G8 summit, and there is real momentum behind this issue."
"We have a real opportunity to make this summer a turning point in breaking down the walls of corporate secrecy and get information on who really owns and controls companies."
EU leaders meeting in Brussels have discussed plans to fight tax fraud and close loopholes used by large corporations to minimise tax payments.
Prime Minister David Cameron said the EU has to be sure "that companies pay taxes and that means international collaboration, sharing of tax information."
Irish Prime Minister Enda Kenny has denied Ireland is cutting special tax deals with multi-national companies, including Apple.
He said: "Ireland has been one of the frontrunners, and will be, in regard to building a new international consensus."
Google boss Eric Schmidt has said law would have to change before the company would consider altering its tax arrangements.
He said the firm would continue to invest in the UK no matter what, adding that Google was proud of its profits, without which there would be a "cost".
Mr Schmidt said: "[Google] makes profits and we're proud of it... less profits has a cost."...the law will have to change for Google to change its tax arrangements."
When he was asked if the current set up was "unethical", he replied: "No."
The Googe boss said the UK was "too important" for the firm."
We will continue to invest in Britain no matter what," he added.
Google boss Eric Schmidt has been asked whether he agrees with Ed Miliband's assertion that his firm's tax arrangements are "wrong", he answers simply "no."
He added that tax is not up to Google, it is up to governments.
Schmidt said "we love the United Kingdom and we follow the tax rules here", and added that if Ed Miliband changed the rules - they would follow them.
The Google boss said the UK was "too important to us" and that they would continue to invest in Britain no matter what.
Taoiseach Enda Kenny has rejected criticism of the Irish tax system after a US Senate committee claimed Apple used the country in a bid to avoid paying billions of dollars in earnings.
On arrival at the European Union summit, he said: "I'd like to repeat that Ireland's corporation tax rate is statute-based, is very clear, very transparent - we do not do special deals with individual companies in relation to that rate."
The Taoiseach said Ireland was one of the first countries to agree a scheme on sharing of tax information with the US.
"Multinationals, in their aggressive tax planning, operate in many jurisdictions. For that reason, Ireland has been very much to the forefront in having and building more international consensus as far as transparency in tax regimes is concerned," he added.
Police say MP Eric Joyce is facing charges of breach of the peace following an incident at Edinburgh Airport on Sunday.
Labour leader Ed Miliband said it was "wrong" that Google had gone to "extraordinary lengths to avoid paying its taxes."
In a speech at Google's big tent event, he said: "I can’t be the only person here who feels disappointed that such a great company as Google...will be reduced to arguing that when it employs thousands of people in Britain...it’s fair that it should pay just a fraction of one per cent of that in tax.
"So when Google does great things for the world, I applaud you but when Eric Schmidt (Google's executive chairman) says, its current approach to tax is just 'capitalism', I disagree.
"And it's a shame Eric Schmidt isn't here to hear me say this direct: When Google goes to extraordinary lengths to avoid paying its taxes, I say it’s wrong."
David Cameron said he believes in low taxes for businesses because he wants "Britain to be a winner in the global race" but said it was important to make sure companies pay what they should.
The Prime Minister spoke as he arrived at an European Union summit in Brussels.
Nick Clegg said he "cannot envisage any circumstances" that would see the coalition collapse before the 2015 general election.
The Deputy Prime Minister added that he "really thought" the Liberal Democrats and Conservatives would continue governing until that time.