One million jobs are threatened by a “complete leadership vacuum” in financial services, following the Brexit vote, the CISI claims.

The professional body has expressed fears that the sector has been left rudderless at a time of uncertainty and left vulnerable to other EU financial centres, which it said were “salivating at the real prospect of attracting business away from the UK”.

The City needed a person, or organisation, to provide reassurance, vision, purpose and dynamism, the CISI said.

Angela Knight, the former head of the British Bankers Association, provided this kind of public leadership during the crisis of 2007, the CISI said.

In a statement, the body said: “The financial services sector urgently needs an articulate, communicative leader who should be highly visible.

“He or she should have been giving press interviews, appearing on TV and radio and exploiting social media to the hilt with a constant message, promoting financial services, calming nervous employees and customers, setting out what is needed in future negotiations and expanding on the positive opportunities ahead.

“Where are all the trade bodies, corporations, local MPs and other organisations that represent the constituent parts of financial services?”

Simon Culhane, Chartered FCSI and CISI chief executive, said: “There have been a number of discussions beneath the radar, but that’s not good enough. What the sector needs is a public, loud, visible champion communicator. Instead there has been almost total silence and zero direction or reassurance.

“There are strong winds from Europe now, threatening our sector. Our industry’s one million employees deserve more than fair weather leaders; they deserve men and women who will step up to the plate quickly.

“If our present captains are not prepared to chart our course to a successful Brexit, as our new Prime Minister and her ‘Ministry for Brexit’ will rightly demand, we – and she – must find and welcome others who are prepared to do so, and quickly.”