The chairman of the UK’s financial watchdog faced calls to resign as angry exchanges over its treatment of whistleblowers dominated the Financial Conduct Authority’s annual public meeting in Edinburgh.

Ashley Alder came under sustained pressure from campaigners at the Assembly Rooms after the FCA announced that one of its own non-executive directors would investigate how the regulator dealt with whistleblower Simon Andriesz before his death.

The meeting on Tuesday was the first time the FCA had held its annual public meeting in Scotland and attracted more than 900 people in person and online. Around 250 people were at the venue.

What was intended as an opportunity to discuss the FCA’s performance over the previous year instead became a highly charged examination of its record on whistleblowing.

Andy Agathangelou, founder of the Transparency Task Force, left his seat to challenge Alder directly and called on him to quit.

He told the FCA chairman: “I would say you are incapable of protecting the integrity of the FCA. I call on you to resign.”

Agathangelou argued that the watchdog could not credibly describe its review into the Andriesz case as independent when it was being led by Lea Paterson, who joined the FCA board as a non-executive director this month.

He accused the regulator of attempting to “control the narrative” around the review and said it should have no role in deciding its terms, timetable or who carried it out.

Alder rejected claims that the process was compromised. He stressed that FCA non-executive directors were appointed by the Government rather than by the regulator itself and said Ms Paterson understood that her role was independent.

The Chairman said the findings of the review would be published and insisted the board would examine the case with “every ounce of seriousness it deserves”.

When Agathangelou continued to press him on whether he would resign, Alder declined to give a yes-or-no answer and moved the meeting on.

Simon Andriesz, a former managing director at financial brokerage BGC Group, had made disclosures to regulators in the UK and US and had repeatedly criticised the way he said his case had been handled.

He also provided information relating to links between former BGC chief executive Howard Lutnick, now US commerce secretary, and convicted sex offender Jeffrey Epstein. His death last month has prompted renewed scrutiny of the support available to whistleblowers and calls from MPs for an external inquiry into the FCA’s conduct.

The FCA has previously acknowledged that it gave Mr Andriesz incorrect information about his whistleblower protection and apologised.

Chief executive Nikhil Rathi defended the regulator’s wider work, describing whistleblowing cases as some of the most difficult the organisation handled.

He said the FCA received around 1,300 cases each year and stressed the importance of providing appropriate support to those involved. The regulator also said whistleblowing reports had increased by around 20 per cent.

The FCA had chosen Edinburgh for the meeting as part of efforts to strengthen its presence in Scotland, where it now employs more than 350 people.

The watchdog also came under pressure over its handling of the Midas Financial Solutions scandal, an Aberdeen-based Ponzi scheme run by jailed financial adviser Alistair Greig.

A group of 95 victims has continued to demand that the FCA cover around £2 million in legal costs they incurred while pursuing the case.

The FCA has previously apologised after an independent complaints commissioner upheld aspects of a complaint over its failure to act on warning signs surrounding Midas, although the commissioner concluded that compensation from the regulator was not appropriate.