Prince Andrew made the pledge after settling the US civil sexual assault case brought by Virginia Giuffre, and agreeing to pay her an undisclosed sum.

He made no admission of liability and has always denied the allegations.

Labour MP Jess Phillips has expressed doubt Andrew could play a constructive role in combating trafficking.

"Those who work in sexual violence [and] human trafficking services are certainly not going to have open arms to his allyship... even if it was just finances," she said.

Ms Giuffre had been suing Andrew in a civil action, claiming he sexually assaulted her on three occasions when she was 17 - which the prince has repeatedly denied.

On Tuesday it was announced they had reached an out-of-court settlement.

A statement from their lawyers said the duke would pay an undisclosed sum to Ms Giuffre and make a "substantial donation" to her charity in support of victims' rights.

It also said the duke regretted his association with late sex offender Jeffrey Epstein. Prince Andrew had previously told BBC Newsnight in 2019 he did not regret being friends with Epstein.

No details of the payout to Ms Giuffre have been made public - and there are calls for more detail about where the money will come from.

The exact amount of the financial settlement has not been revealed but reports have speculated that it could run into millions of pounds. The duke receives a Royal Navy pension and a stipend from the Queen's Duchy of Lancaster income.

In a statement released on Tuesday, Andrew also pledged to "demonstrate his regret for his association with Epstein by supporting the fight against the evils of sex trafficking, and by supporting its victims".

Gabrielle Shaw, chief executive of the National Association for People Abused in Childhood (Napac), said: "Napac acknowledges and is grateful to the many generous fundraisers and donors who are survivors or supporters of survivors themselves," she added.

"With this trust being core to Napac's approach, any support for the charity that Prince Andrew may offer would raise significant concerns as to the ethical implications of accepting money or patronage from an individual who is a suspected perpetrator and who had ties to a convicted offender."

Beyond the Streets, a charity working to end sexual exploitation, said it was unlikely it would accept any support offered by Andrew.

"We think the priority of organisations who support women who have been exploited should be on their beneficiaries and not on the profile and activities of those who support them," a spokesperson said.

"This is particularly important in situations such as this where it could be perceived that there is a benefit to the potential supporter and there have been serious accusations involved."

Jayne Butler, chief executive of Rape Crisis England and Wales said while it had not been offered any support, financial or otherwise by Andrew or Ms Giuffre, it would not do so "without consulting with our Rape Crisis member centres and with survivors".

Ms Phillips, shadow minister for domestic violence and safeguarding, told BBC Radio 4's Woman's Hour: "It's going to take a huge amount of effort and I think it will be incredibly hard for Prince Andrew to make that effort."

Prince Andrew, Virginia Roberts - now Virginia Giuffre - and Ghislaine Maxwell in 2001

Ms Giuffre, now 38, claims she was the victim of sex trafficking and abuse by financier Epstein from the age of 16. Epstein died while awaiting trial in 2019.

She claimed the duke sexually assaulted her on three separate occasions in London, New York, and on Epstein's private island in the US Virgin Islands.

In a 2019 interview with BBC Newsnight, Prince Andrew said he didn't recall meeting Ms Giuffre and that an incident in which she alleges they had sex at the Belgravia home of Ghislaine Maxwell "didn't happen".

In January, a New York court ruled that the civil action against him could go ahead.

Shortly afterwards, Buckingham Palace said the prince's military titles and royal patronages had been returned to the Queen and that he would defend Ms Giuffre's civil case as a "private citizen".

Is there any way back for Prince Andrew?

If Prince Andrew had gone to court in the US to fight it out with Virginia Giuffre, it would have made headlines as tall as a New York skyscraper.

That royal disaster zone has been averted by an out-of-court settlement.

But it comes with high costs to Prince Andrew, both financial and reputational, and it will be a long road back before there is any chance of clearing his name in terms of public opinion.