Deutsche Bank is considering whether it needs to move thousands of staff from London to Frankfurt following Britain’s decision to leave the EU, one of its top executives said.

After Britain triggered Article 50 last month and has begun divorce talks with the EU, financial firms have stepped up planning on how to deal with any disruption that might ensue, such as losing access to the bloc’s single market.

“For front office people if you want to deal with EU clients you need to be based in the EU, in continental Europe. Does that mean that I have to move all the front office people to Germany or not?” said Deutsche Bank’s chief regulatory officer Sylvie Matherat.

“And we are speaking of 2,000 people – that’s not a small number,” she told a conference hosted by Frankfurt Main Finance, a group that promotes the German financial capital.

Matherat said that any such move would require the bank to build up its information technology in Frankfurt and would also depend on local regulators’ stance on how trillions of euros in future deals should be cleared or processed.

“What are you going to do: do you have the technical capacity to move it? Do you have the willingness of the local regulators to supervise something that looks like hundreds of trillions in terms of exposure,” Matherat said.

She said that some local supervisors are also asking for risk management to be done locally, a demand that would require more jobs to be moved.

“It means another 2,000 people. Everybody needs clarity – and the sooner the better.”

She said the bank had 9,000 staff in Britain.

Despite Deutsche considering such moves, it is likely to retain a large presence in the UK and recently chose a new office for its London headquarters.