The financial district of Canary Wharf, in London. Photo: Neil Hall/Reuters

Shares in Britain’s top banks suffered further deep losses yesterday as fears about the fallout from Brexit sparked a litany of earnings downgrades and sell-offs by shell-shocked investors.

Shareholder anxiety about Britain’s decision to quit the EU escalated despite calls for calm from British Finance Minister George Osborne following a weekend of political chaos in Britain and the eurozone.

Barclays, Lloyds Banking Group and Royal Bank of Scotland were among the hardest hit with falls of 11 per cent, nine per cent and 14 per cent respectively in dramatic early trading that sent the STOXX Europe 600 bank index to its lowest since June 2012.

After lauding efforts by banks to cut costs, streamline operations and beef up balance sheets in recent months, a string of analysts said the likelihood of catatonic interest rates and falling credit demand in the wake of Brexit had put earnings prospects and dividend growth at risk.

“The market is justifiably concerned about the sustainability of earnings in a macroeconomically uncertain environment, and the ability to withdraw excess capital,” RBC Capital said, in a note that slashed its price targets for British banks by 30 per cent.

“UK rates markets are now pricing in a 25 basis point rate cut and no rate increases again until 2019. It seems at least that the uncertainty will lead to an economic slowdown,” RBC said.

European banks did not escape.

Barclays analysts downgraded earnings expectations for a slew of continental lenders including Bankia, Banco Populare, Intesa, UBI and Unicredit, citing rising political risk and fading hopes for a lower cost of equity.

“The risks of anti-EU contagion, coupled with a number of binary events in the coming months – an Italian referendum in October, US, French and German elections beyond this – suggest it will be difficult for banks’ costs of equity to fall anytime soon,” the Barclays note said.

A spokesman for Italy’s Economy Ministry said yesterday the government was looking at various options to try and prop up the country’s bank stocks.

After double-digit stock falls on Friday, investor nerves were frayed further by the resignation of EU Commissioner Jonathan Hill on Saturday, the man many hoped would renegotiate ‘passporting’ privileges that have turned British financial services into the country’s most lucrative exporters.

JPMorgan used its note to highlight the mounting challenges faced by lenders with significant investment banking operations, cutting 2018 earnings per share estimates for the sector by 28 per cent and rewriting recommendations for Morgan Stanley, Goldman Sachs, Deutsche Bank, UBS and Credit Suisse.

JPMorgan estimated average 13 per cent earnings per share cuts in both 2017 and 2018 for European banks, on the back of lower loan growth and expected increases in both bank funding costs and bad debt provisions.

The Wall Street heavyweight downgraded all domestic-focused UK lenders to neutral and underweight positions but joined rival analysts at Deutsche Bank in conferring preferred status on Asia-focused Standard Chartered and Europe’s largest bank HSBC, describing both as defensive options.

Away from the stock markets, ballooning credit default swap (CDS) prices offered further insight into wilting investor confidence in the ability of European banks to ride out the political and economic storm triggered by Brexit.