Staying in the European Union could add £58bn a year to the British economy by 2030, according to a new report out this week.
The study, commissioned by the Britain Stronger in Europe campaign for the UK to remain in the EU, also found that avoiding a so-called Brexit could bring 790,000 jobs to Britain over the next 15 years.
The Centre for Economics and Business Research (CEBR), which conducted the study, said that the values added would come from further economic reforms.
But the CEBR added that even without reforms, UK exports to the EU are worth £187bn a year to the domestic economy – a number that could rise to £277bn a year by 2030.
Britain Stronger in Europe chair Lord Stuart Rose said that the report sets out “potential future benefits of our EU membership” and makes clear “not only that Britain is better off in Europe now, but that in the coming years we have more to gain”.
Meanwhile, Dominic Cummings, campaign director of the Vote Leave pro-Brexit campaign, dismissed the findings, saying: "For years politicians like Nick Clegg and Peter Mandelson have been telling us that the EU would reform and do less. Yet every year the EU takes more power and money."
"The Chairman of the EU-funded BSE campaign has admitted that if we vote to leave, nothing bad will happen to our economy," Cummings added. "If we Vote Leave we will get a free trade deal and we will be able to end the supremacy of EU law in the UK."
Britain Stronger in Europe has denied receiving funding from the EU.