By Jonathan Davies

The City would have "nothing to fear" if the UK votes to leave the EU, according to a report by the Business for Britain campaign group.

Just yesterday, ratings agency Standard & Poor's warned that global banks could leave London if the UK exits the UK.

But the report by Business for Britain says international banks would have no reason to leave the UK and challenged claims that leaving the EU would hurt the UK's financial services sector.

“Britain and its financial services industry have nothing to fear from separating from the EU’s institutions,” the report said.

The report comes as Prime Minister David Cameron heads to Berlin to start formal negotiations with German Chancellor Angela Merkel over a reform of the UK's relationship with the EU.

Business for Britain claim that the UK's national interests would be best served by leaving the EU, if Mr Cameron cannot secure reform.

The report said: "It is very unlikely that the EU would try to deny the City access to European capital markets: the EU itself would be harmed if it cut ties with the City of London. Further, the appeal to large multinational financial institutions of settling in the City is not simply Britain’s EU membership. The UK has a range of attractions to these firms."

It suggests that, due to promises made to the World Trade Organisation by the EU, that Britain's financial services could still gain access to EU markets: "Considering the sheer lack of UK influence over EU laws this would not be materially different to the situation we find ourselves in today. In fact, by reclaiming a seat at key international [financial] institutions, the UK may gain a more significant role in drafting the international rules that the EU then transcribes into its own laws."