SHARES in Royal Bank of Scotland have plunged more than four per cent in early trading after first quarter earnings fell at the state-backed institution amid continuing Brexit uncertainty.

The bank, which announced the departure of chief executive Ross McEwan yesterday, reported an operating profit of £1 billion for the quarter ended March 31, down from £1.2 billion last time.

Royal’s net interest margin, a key performance measure, declined to 1.89 per cent from 2.04 per cent, amid what Mr McEwan told reporters was “unprecedented pressure” in the mortgage market, with loan to values at “historic lows”.

Total income was £265 million lower at £3bn "as we continued to see competitive pressure affecting our margin," he added.

The New Zealander, who is stepping down after five and half years in charge, flagged the continuing effects of Brexit uncertainty, which is causing big businesses to delay investment decisions.

He said it was a “solid set of results" against a backdrop of economic and political uncertainty and competitive pressures.