French banks with operations in the UK have been encouraged to draft contingency plans that include pulling thousands of staff out of the City back to Paris, as polls tighten ahead of the EU referendum next week.
It has been reported by The Sunday Times the banks are concerned that London-based operations could lose the right to operate freely across the eurozone under the European Union's passporting rules should a Brexit occur.
BNP Paribas, Société Générale and Crédit Agricole are the largest French banks with operations in London.
Last week the deputy mayor of Paris said the French capital would be "rolling out the red carpet" to those involved in financial services based in London, according to the publication.
Meanwhile, US giant Morgan Stanley has reportedly written up contingency plans to move 1,000 workers out of London, potentially to Frankfurt.