Optimism about the outlook for Britain’s financial services sector is at its lowest point since the financial crisis, a survey of finance firms showed on Monday.

The latest survey of 115 financial services firms by business lobby CBI and consultancy PwC found that optimism fell during the three months to September, the third quarter in a row that it has dropped, marking the longest decline since the depths of the financial crisis in 2009.

Over half of all financial firms surveyed said the general impact of Britain’s Brexit vote was negative, with only one in ten firms seeing any upside.

“With firms voicing strong concerns about the impact of Brexit, especially the risks to the wider economy in the years ahead, the government must allay their unease with clear plans for negotiations to leave the EU,” CBI Chief Economist, Rain Newton-Smith, said in a statement.

Britain’s financial industry is the economy’s biggest tax earner as firms benefit from a European Union “passport” allowing them to operate across the bloc from a British base.

Britain will have to negotiate new trading terms with the EU and it is unclear if full passporting for financial services will continue so that companies can avoid having to invest in a new base inside the EU.

The Lloyd’s of London insurance market said last week it was planning to move some underwriting activity to the EU if there is no full access to the single market.

“Many of our clients are considering their options, including potential restructuring and relocation of their businesses,” Andrew Kail, UK financial services leader at PwC, said.

“However, it’s the domino effect on people, productivity and position as a financial hub that must be guarded against.”

The survey also showed that a squeeze on profitability from very low interest rates, changes in technology and strong competition were also weighing on business sentiment.

Optimism was “broadly stable” in life and general insurance, and fell only slightly among banks, but dropped sharply among finance houses, building societies and investment managers.

Several property funds still bar investors from withdrawing their money after commercial real estate took a hit following the vote in favor of Brexit.

Growth in overall business volumes is expected to slow in the coming quarter, the survey, which was conducted between August 16 and September 1, said.