The British banking establishment has warned about the difficulties that could be caused for the financial sector if the UK loses its current relationship with the EU, calling for closer links to be established with Brussels.
In a submission to a Treasury review, the British Bankers' Association (BBA) argued the current balance of power between EU apparatchiks and the UK is broadly appropriate, allowing companies sufficient leeway while still retaining a degree of collaboration.
However, it warned that under the current system Britain remains under-represented in Brussels due to a dearth of resources, reports the Financial Times.
A host of other groups have chimed in on the issue, highlighting just how widespread concern is in the sector about the possibility of leaving the EU.
Jim Cowles, Citigroup's chief executive for Europe, the Middle East and Africa, told the Financial Times any decision to disengage from the single market could have drastic effects on the effectiveness of the British economy.
Clients of his company are experiencing "mounting concern" that they will be unable to use the UK as a regional base if its relationship with the EU changes, he explained.
"It's not that international companies will stop investing in Britain, but their investment just won’t be at the scale we have become accustomed to," he argued.
The Citi and BBA interventions were made in submissions on financial services to the government's "balance of competences" review, which was set up to assess the relationship between Brussels and Westminster ahead of any further decision on EU membership.
Other concerns raised included the BBA's suggestion that fewer Britons are now working in European financial institutions and the feeling that not enough is being done to give British interests a platform on the continent.
"Jobs and the growth of Britain’s economy depend on maintaining and increasing exports to the EU, particularly as the European economy begins to recover. This will be a much more difficult task if businesses have to contend with a Britain that has decided to exit the EU," concluded Mr Cowles.