The outgoing chair of Barclays has issued a stern rebuttal of activist investor Edward Bramson and his campaign for change at the UK bank, saying his presence is “unnecessarily destabilising for management and the talent we employ”.

In documents sent to investors ahead of Barclays’ upcoming annual general meeting, John McFarlane said that allowing Bramson a seat on the board would be “detrimental to the company and shareholders as a whole”.