Wealth managers at Swiss bank Credit Suisse have advised their high-net worth clients to think about moving assets out of the U.K. due to the uncertainty surrounding Brexit, according to a report from the Financial Times.

The FT reported Tuesday that clients with a net worth of at least $30 million, known as ultra-high net worth individuals (UNHWI), were advised they might want to "accelerate" plans to move their investments out of London before Prime Minister Theresa May's upcoming vote in Parliament in the third week of January.

On Monday, May said she intended to hold the vote on her Brexit plan in the week starting Jan. 14. Britain's leader of the opposition, Jeremy Corbyn, tabled a motion of no confidence in May, saying it was unacceptable for Parliament to wait another month to vote on the deal.

U.K. lawmakers were initially scheduled to have their say on the terms of Britain's withdrawal from the EU last week but the prime minister delayed the vote, admitting she was likely to lose.

This has led to a lot of uncertainty surrounding the path for Brexit — something that markets and investors don't like. The FT reported in October this year that multimillionare investors were rushing to the Channel Islands and Switzerland to set up accounts and also preparing to emigrate instead of risking the possibility of a "wealth tax" if Labour leader Corbyn were to come to power.

However, not everyone agrees that leaving the U.K. is the right course of action. "We certainly wouldn't encourage clients to get their money out and run," one banker, who asked not to be identified, told the FT. "Our role as wealth advisers is to calm some of the hysteria going on rather than add to it."

The bank told CNBC Tuesday that "Credit Suisse does not currently hold a house view that clients should move assets out of the UK due to Brexit or other political developments in the UK."

Read the full report here.