Ed Miliband has warned that Tory plans to hold a referendum on Britain's membership with the European Union pose a "clear and present danger" to jobs and prosperity.
The Labour leader will use the first day of the official campaign period to warn that David Cameron's plans for a referendum in 2017 will lead to "two years of uncertainty".
In a speech at Bloomberg in London today, Mr Miliband will say businesses will face years of "chaos" and will be left unable to plan for the future if the the Tories win power on May 7 and the referendum goes ahead.
Miliband will say that his party will not "condemn this country to years of uncertainty, years of insecurity, by threatening our European future".
David Cameron may never arrive in Brussels in a Prime Ministerial motorcade again, so he used this occasion to make his European pitch.
Before he puts a referendum before the British people, he must put a renegotiation to the 27 other members of the European Council. But the President of the European Council Donald Tusk compared Cameron’s plan to a Tom Cruise movie - Mission: Impossible.
David Cameron has launched a new drive to bolster former communist states under pressure from Vladimir Putin as the stand-off between Russia and the West over Ukraine continues.
The Prime Minister is setting up a £20 million Good Governance Fund to strengthen democratic institutions across a series of Eastern European states to help them counter intimidation from the Kremlin.
British officials said the scheme is based on the Know-How Fund set up by Margaret Thatcher following the fall of the Berlin Wall to help Poland and other former Soviet bloc states make the transition to democracy.
The move came as EU leaders meeting in Brussels agreed there would be no easing of sanctions against Moscow until it was clear the Minsk ceasefire deal was being fully honoured.
Greek Prime Minister Alexis Tsipras said he was "more optimistic" after three hours of talks with the leaders of Germany, France and EU institutions on the possibility of further financing.
"I'm more optimistic after this deliberation. I think that all the sides confirmed their intention to try to do their best to overcome the difficulties of the Greek economy as soon as possible," Tsipras said on leaving the talks in Brussels.
The prime minister said all parties had promised they would work to restore Greece's funding ability as soon as possible.
Greece has promised to speed up implementing its extended bailout agreement and send a full list of detailed reform proposals to its eurozone partners, German Chancellor Angela Merkel has said.
Following an overnight mini-summit with Greek Prime Minister Alexis Tsipras, French President Francois Hollande and heads of the main EU institutions, Merkel said euro-area finance ministers are ready to meet soon to evaluate the reform plans.
However, she declined to set any date for releasing further aid to the cash-strapped Greek government, saying that depended on a positive evaluation of the reform proposals.
The Greek prime minister is getting another talking-to tonight at a meeting in Brussels about his country's debts.Read the full story ›
David Cameron is expected to take up the cause of hundreds of online "micro-businesses" threatened by changes in European tax rules at an EU summit in Brussels today.
The Prime Minister is planning to raise new VAT regulations for automated digital services at the summit - his last before the General Election takes place.
Cameron is planning to tackle European Commission president Jean-Claude Juncker over the issue on the margins of the summit in the hope the commission will bring forward solutions by the summer.
Most voters want all parties to commit to holding an in/out referendum on Britain's membership of the European Union, research has found.
68% agreed that a national poll should be a party pledge across the political spectrum with 32% disagreeing, the online survey by uSurv found.
Women and men were equally enthusiastic for such a commitment and support was strongest among the over 40s, although 59% of 18-29 year olds and 66% of those aged between 30 and 39 were also in favour.
David Cameron has promised the British people a vote on whether to pull out of the EU by the end of 2017 if he remains in No 10 after the general election.
Labour and the Lib Dems have said they will only hold a referendum if there is a proposal to transfer further powers to Brussels.
uSurv surveyed 1,000 respondents online yesterday and results reflect the gender and regional breakdowns of the UK according to the UK 2011 census.
Labour's shadow chancellor Ed Balls has said that Britain "shouldn't flirt" with the idea of exiting the European Union.
He told attendees at the British Chambers of Commerce annual conference that Britain walking out of the EU was the "biggest risk to our economy in the next decade".
European foreign ministers have called on Russia to free female Ukrainian army pilot Nadezhda Savchenko.
Savchenko, 33, was captured by pro-Russian separatists while fighting in a volunteer battalion in eastern Ukraine last June.
The Ukraine government says the separatists took Savchenko to Russia where she was arrested and accused of killing two Russian journalists.
Foreign ministers gathered for a meeting in Brussels held posters which read: "We call the Russian authorities to free illegally abducted Ukrainian Pilot #FreeSavchenko."