Rival camps in the battle for Britain's future in the EU will use fresh research on its impact on business to back their case following the publication of two reports on the single market.
Former Marks and Spencer boss Lord 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% 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."
But research by think tank Civitas found Britain's membership of the single market has failed to have a significant impact on export growth.
Its analysis of official trade statistics found the bloc has boosted the exports of non-EU countries more than its members, with Britain recording slower export growth than any of the other founding nations.
Growth of exports between member states during the common market was 4.7% but has fallen to 3% in the single market, the research said. UK export growth fell from 5.38% to 3.09% over that period, it added.
The research extends growth trendlines from the common market years of 1973 to 1992 and the single market between 1993 and 2012.
It found UK export growth in the single market was 22.3% lower than it would have been had it continued at its rate during the common market.
Exports between the 12 founding members of the single market are 14.6% lower than if they had continued to grow as they had done under the common market, the report adds.
Academic Michael Burrage, who wrote the report, said: "While the single market cannot be counted a success in export terms for the EU as a whole, for the UK it must be counted at the very least a massive disappointment, and not far short of a disaster.
"There has been no discernible benefit for UK exports to fellow members from the single market programme."
Vote Leave chief executive Matthew Elliott said: "The unquestioning mantra that the single market has been good for British trade is wrong and should be challenged as this research makes crystal clear."