Edward Bramson, the activist investor targeting Barclays, has called for a shake-up of the bank’s board, saying he has lost faith in his ability to influence change as an outsider after being denied a non-executive role.

Bramson, whose firm Sherborne Investors now holds a stake of more than 5.5% in the UK lender, is likely to seek a “shareholder vote to change the composition of the board” after being spurned.