British businesses are growing increasingly 'indifferent' to the prospect of Britain leaving the European Union next month, a survey published on Monday (23 May) has shown.

According to the latest poll from ICSA: The Governance Institute, optimism among FTSE 350 firms reached its lowest level in four years, on the back of global uncertainty and "considerable frustration arising from the tide of new regulation and legislation".

The poll found only 43% of the businesses surveyed described a Brexit as "potentially damaging", sharply lower than 70% in December, while ICSA added just over 50% had given thought to the implications of Britain leaving the 28-country bloc.

The number of companies that believed being part of the EU had a positive impact on their business also fell dramatically. The EU's appeal tumbled from 61% six months ago to 31%, according to ICSA, who added that FTSE 100 firms tend to be more vocal in their support to remain than their FTSE 250 counterparts.

Meanwhile, a separate survey from Lloyds showed a mix of turmoil in financial markets worldwide with new regulation posing a serious threat to economic growth in the next 12 months.

Approximately 40% of the chief executives of the 110 multinational banks, insurers and asset managers polled by Lloyds said confidence declined on the back of worries related to a renewed worldwide slowdown.

A new set of regulations was forcing companies to prioritise "process over performance and strategy", Lloyds said, adding that 44% stated regulation had "come at a cost to economic growth".

"This year has already proved to be a very challenging year for the UK financial services sector and this has dented confidence across the sector," said Ed Thurman, managing director of Lloyds financial institutions.

"The headwinds of economic volatility and new regulation, do not show signs of abating, but the overwhelming view is that the UK will ultimately fare as well as, or better than our G7 peers."

However, despite concerns over excessive regulations, the survey found a large majority of respondents believing that regulatory reforms have resulted in greater transparency and better protections for UK customers.