Fears of a mass exodus of jobs sparked by Britain's vote to leave the European Union in June are rapidly becoming a reality, research claims.

Brexit has acted as the catalyst for major US banks to carry out 'radical surgery' on UK operations, including cost cutting and shifting hiring plans from London to rival cities, executive recruitment firm DHR International said.

London Stock Exchange boss Xavier Rolet last week warned over 100,000 UK jobs could be at risk if the euro clearing business is moved abroad as a result of Brexit.

Fears becoming reality? Fears of a mass exodus of jobs sparked by Britain's vote to leave the European Union in June are rapidly becoming a reality, research claims

Stéphane Rambosson, managing partner of DHR International, said some firms were using Brexit as a 'handy excuse for getting on [with] the unpleasant task of moving jobs outside London.

'Firms were already making plans to move middle and back office roles out of London in order to cut costs, but now Brexit has acted as a catalyst for radical surgery, providing firms with the impetus to act on these plans immediately.'

He said businesses were eyeing cost savings of up to 40 per cent by relocating roles to Warsaw, Lisbon and Dublin, while India, Malaysia and China were also set to benefit from a move to offshore more roles.

Rambosson adds: 'It's been widely speculated that US banks would shift their focus away from London post-Brexit but now this is definitely starting to happen.

'A number of US banks have shifted their hiring for senior positions in corporate and investment banking to locations such as Paris and Frankfurt as part of the first step in expanding their presence in mainland Europe.'

Concern: Xavier Rolet, boss of the London Stock Exchange, claimed last week that 100,000 jobs could be at risk if euro clearing practices are moved from the UK

JP Morgan, HSBC and Goldman Sachs all said prior to the vote that thousands of jobs in the City of London could be moved to the continent if Britain voted to leave the EU.

Xavier Rolet, boss of the London Stock Exchange, claimed last week that 100,000 jobs could be at risk if euro clearing practices are moved from the UK if the powers that be in the EU decide it should be carried out within the EU.

Commenting on how many jobs could be at risk, Rolet said: 'We estimate, conservatively, that at a very minimum 100,000 jobs, in risk management, compliance, middle office, back-office support functions -by the way not just in London, up and down the country - are implicated in supporting this business and clearly could be at risk.'

Moving on? JP Morgan, HSBC and Goldman Sachs all said prior to the vote that thousands of jobs in the City of London could be moved to the continent if Britain voted to leave the EU

In the weeks after Britain voted to leave the EU, the Boston Consulting Group warned up to 80,000 jobs could be shifted out of London to rival financial centres across Europe in the wake of the Brexit vote, with Frankfurt trumpeted as the 'most attractive location' among bankers.

Despite such projections, Britain's post-Brexit job prospects is not a clear cut issue. Some analysts believe a post-Brexit 'wholesale exodus' from London is unlikely.

Leith Khalaf, a senior analyst at Hargreaves Lansdown, said: 'I suspect most international banks have drawn up contingency plans for Brexit, but it’s too early for them to push too many buttons because the precise nature of Britain’s withdrawal from the EU is vitally important.

'If financial institutions are allowed to continue selling their wares into Europe from the UK, then its largely business as usual.

'Until this is clearer there is unlikely to be a wholesale exodus from London, though at the fringes new positions may go to the continent instead, if all other things are equal.'