Unveiling Labour’s business manifesto at Bloomberg’s headquarters in London this morning, Miliband said the prime minister had repeatedly caved into demands from backbench MPs who want to leave Europe.

He said Labour’s focus was on delivering reforms from within the EU to promote growth, the EU budget, immigration and international trade agreements.

Business leaders as well as political opponents have questioned Labour’s commitment to supporting business and its seriousness about tackling the UK’s debt pile of nearly £1.5 trillion.

Conservatives condemned Miliband for failing to mention the economy in a speech to the Labour party conference in September last year.

The new 22-page business manifesto is the first of a series of documents the party will publish on a range of issues in coming weeks. It sets out how, if elected to form the next government, it would:

- Cut the deficit every year, with a surplus happening “as soon as possible”

- Return Britain to a leadership role within the EU

- Set up a national infrastructure commission, to tackle long-term infrastructure needs

- Cutting and freezing business rates on 1.5 million small business properties

- Establishing a “proper” British Investment Bank to help SMEs raise finance

- Compel young people to study English and maths to 18, helping to reduce the skills gap

- Create more apprenticeships for young people

Miliband said: “There could be nothing worse for our country or for our great exporting businesses than playing political games with our membership in Europe.

“David Cameron used to understand that. But in the past five years our place in the European Union has become less and less secure. He used to say he would campaign to keep Britain in Europe. But now he won’t rule out campaigning to leave.

“It threatens to leave UK businesses out of a market that gives them access to the world’s largest trading bloc. It’s simply the wrong direction for our country.

“If you care about strong foundations, if you care about long-term stability, if you care about prosperity, then Britain must be a committed member of a reformed European Union, not threatening to leave, not locked out of the room.”