Aviva and Phoenix have become the first major firms to publicly quit the Confederation of British Industry (CBI) following a second rape allegation from a woman working for the business group.

The FTSE 100 firms have pulled their membership to the group after the latest in a raft of misconduct allegations facing the CBI.

An spokeswoman for Aviva, one of the UK’s biggest insurance firms, said: “In light of the very serious allegations made, and the CBI’s handling of the process and response, we believe the CBI is no longer able to fulfil its core function – to be a representative voice of business in the UK.

“We have therefore regrettably terminated our membership with immediate effect.”

A spokesman for savings and retirement giant Phoenix said: “Further to the allegations reported this morning, we have taken the decision to resign our membership of the CBI with immediate effect.”

The crisis facing the trade group deepened after The Guardian reported on Friday that the woman claimed she was raped by two male colleagues.

The woman claimed the alleged rape took place while she was unconscious following a night-out while working at a CBI office abroad.

She said she had no recollection of the rape itself but had described in detail the physical signs that led her to believe she was raped, and was later presented in the office with an explicit photograph.

It is the second claim from a woman that she was a victim of rape at the organisation.

Previously, a member of staff alleged that she was attacked by a manager on a summer boat party in 2019.

Details of the new rape allegation have been passed on to police.

City of London Police were already investigating the previous rape allegation, alongside a series of other misconduct allegations from around a dozen workers.

Separately, The Guardian also reported on Friday that a woman based at the organisation’s London office claimed she was stalked by a male colleague in 2018.

In response, CBI president Brian McBride said: “The latest allegations put to us by The Guardian are abhorrent and our hearts go out to any women who have been victims of the behaviour described.

“While the CBI was not previously aware of the most serious allegations, it is vital that they are thoroughly investigated now and we are liaising closely with the police to help ensure any perpetrators are brought to justice.

“We recognise the substance of the harassment report outlined as relating to an allegation made and investigated in January 2018.

“The finding of harassment was upheld and a sanction was imposed.

“However, the CBI does not recognise many of the most serious elements of The Guardian story relating to harassment, including the assertion that the individual had told the CBI of feelings of a sexual and violent nature towards the victim; and that he had followed her home.”

The CBI added it is expecting a further report from the law firm conducting an internal investigation later on Friday and will announce steps to “bring about the wider change that is needed” early next week.

On Thursday, the CBI confirmed it passed fresh information to the police regarding a report of a “serious criminal offence”.

It said it was “liaising closely” with the authorities and has urged anyone with further information to come forward.

Separately, former CBI director-general Tony Danker was sacked last week after being accused of making unwanted contact with a woman who works for the organisation.

On Wednesday, he said his reputation has been “totally destroyed” by the allegation and claimed he has been made a “fall guy” for a wider crisis.

Mr Danker told the BBC his name had been wrongly associated with separate claims, including the rapes which allegedly happened before he joined the CBI.

After initial allegations, the business group also suspended three other employees and hired a law firm, Fox Williams, to carry out an internal investigation.