Fresh data on Europe to divide campaign groups

Former Marks and Spencer boss Stuart Rose will release analysis that shows the EU is worth an average of £670,000 in extra trade for each business that exports or imports goods within the trade bloc.

Vote Leave, meanwhile, will seize on the findings of a study by a think tank that claims the single market has had “no discernible benefit” for UK exports and has proved “not far short of a disaster” for Britain.

Prime Minister David Cameron will head to Brussels next month to try to finalise renegotiations on Britain’s relationship with the EU before putting the deal to the country in a referendum by the end of 2017 at the latest.

Britain Stronger In Europe will point to research by the Centre for European Reform that found Britain’s goods trade with the EU is 55 per cent higher as a result of its membership. The “EU effect” was worth around £133bn to the 200,000 export and import companies in the UK in 2014, it said.

UK-based financial services firms would lose the right to operate across the EU, the campaign will say.

It will also call on Eurosceptics to set out evidence on what future trade deals would look like outside the EU and insist most British businesses want to remain in.

Britain Stronger In Europe chairman Lord Rose will say: “As the former chief executive of Marks and Spencer, I saw first-hand how being in Europe and the single market benefits British businesses.

“The single market benefits firms big and small because they can trade tariff-free with a common set of regulations across the whole of Europe.

“We simply cannot get the benefits this brings outside the EU.”