A poll of over 300 respondents found that while the majority (55%) think an EU exit would have a negative financial impact, 14% advocate a ‘third way’ – similar to that adopted by Norway, Iceland and Switzerland – which would involve membership to the European Economic Area but without formal vote over EU laws.

 Just one in ten believe a British exit (Brexit) would be advantageous. Dave Way, managing director at Marks Sattin, said: ‘Accountancy and finance professionals across the UK favour the security of remaining within the EU and continuing as part of a substantial organisation that can exercise real clout on the world economic stage.’

A study published this week from two German research institutes, the Bertelsmann Stiftun and Ifo Institute calculates a Brexit could cost the UK as much as €300bn (£215bn), or 14% of GDP. It says that even if an independent UK had a trade agreement with the EU, the costs would still outweigh the benefits.

The Marks Sattin survey suggests finance professionals are divided on whether current uncertainty over the prospect of an upcoming EU referendum is damaging confidence in the UK economy. While 45% agree that it is, 40% do not think the economy is suffering.

Way said: ‘We are already hearing rumblings from financial institutions that the UK’s attractiveness as a financial hub is looking less rosy. But a significant proportion of finance professionals remain optimistic and the dominant theme of 2015 has been economic recovery.

'However, the latest government data shows GDP growth slowing in quarter one of 2015 compared to last year.

‘Unfortunately we may not be in any clearer position following the imminent election with many political analysts placing their bets on a 1974-style double election scenario – the uncertainty may play out for several months.’