Ed Miliband has placed Britains membership of the European Union at the heart of Labours general election pledge to build a fairer economy.

The Labour leader said the UK was better off in the EU and said David Cameron was playing political games with the countrys membership by dithering on its relationship. Speaking at Bloombergs headquarters in London, Miliband said businesses faced uncertainty, while the Conservatives threatened to leave the EU.

Our long-term future lies inside, not outside, the European Union, Miliband said. There could be nothing worse for our country or for our great exporting businesses than playing political games with our membership of the EU. David Cameron used to understand that. But in the past five years, our place in the European Union has become less and less secure.

Miliband also said Camerons announcement that he would not serve a third term would create a jostling of position between candidates over who could be the most extreme on Europe.

The job of the next prime minister is to open new markets for ‎business not close them off, he added. And we should be reforming Europe from the inside. To build an EU that supports the needs of business. To build an EU that spends its budget wisely. To build an EU with fair rules on immigration.

On the same day Parliament was dissolved, Miliband vowed to add more skilled workers to the workforce if he is elected prime minister and outlined plans for a British Investment Bank.

We will create a British Investment Bank, supporting a network of regional banks. To invest in businesses in every single part of Britain. And we will have a market share threshold to make sure there is more competition in business banking on the high street. Real choice for businesses like yours. We need an effective banking sector and we will work with our banks to ensure that they work for our businesses once again.

In an appeal to businesses, Miliband said Labour would keep corporation tax at 20-21% and set up a new independent National Infrastructure Commission.