More than a quarter of major U.K. financial services firms have said they will move staff or operations abroad, or are reviewing their domicile because of Brexit, according to consulting firm EY.

That’s a 50 percent increase this year in the number of banks, insurers and asset managers which have publicly fleshed out their plans as the countdown ticks toward Britain’s March 2019 withdrawal from the European Union, said EY, which is monitoring 222 firms. Eight of the biggest investment banks, including Goldman Sachs Group Inc., JPMorgan Chase & Co. and Deutsche Bank AG, have detailed their contingency arrangements in the past fortnight.

Finance companies are preparing to move some British-based operations into new or expanded bases inside the EU after Prime Minister Theresa May began the formal process for quitting the 28-nation bloc. London could lose 10,000 banking jobs and a further 20,000 roles in financial services, according to the Bruegel think tank, while other estimates range from as little as 4,000 to as many as 232,000 positions.

“The number of financial institutions who are publicly committing to concrete action in response to Brexit has increased, but it’s still a minority and is driven by the tight timetable rather than by politics,” EY U.K. financial services leader Omar Ali said in a statement. “The more complex the organization, the longer it is going to take to create workable contingency options, and so investment banks in particular are putting their plans on record.”

Separately, firms in the capital’s financial district don’t think the two-year Brexit negotiation period is long enough either for the U.K. to redefine its trading relationship with the EU or for companies to restructure their businesses, according to Freshfields Bruckhaus Deringer LLP.

Firms want a lengthy phased implementation period after March 2019 to adapt to the new rules, the law firm said in a report Monday.