Millions of pounds on unused Oyster cards could help fight homelessness in the capital this Christmas, a London mayoral candidate has said.

Liberal Democrat Siobhan Benita said the public could hand in cards they are not using, and Transport for London (TfL) could donate the balance to charity.

She called for the Mayor and TfL to adopt her Oysters For Christmas campaign after a sleep-out for homelessness charity Centrepoint in Queen Elizabeth Olympic Park last night (Tuesday).

Rough-sleeping in London hit a record high last year, with almost 9,000 people sleeping on the streets, according to research by the Combined Homelessness and Information Network.

Last month, Sadiq Khan doubled City Hall’s rough-sleeping budget to more than £19.2 million, funding more shelters and support services.

The Mayor’s fundraiser for homelessness has raised almost £10,000 for London charities this year.

But Ms Benita believes an Oyster donation scheme could do more.

She said: “If Sadiq Khan is serious about helping the thousands of people who are homeless or at risk of homelessness in London this Christmas, he could act now and do something which would have a real impact on vulnerable people’s lives over the festive period and beyond.”

There is now £400 million on Oyster cards that have not been used in the past year – and the figure has doubled since 2016.

TfL says inactive cards may belong to tourists who visit the city occasionally, or Londoners who keep their card as a reserve.

Around half of the unclaimed money is deposits – the £5 fee paid when you get an Oyster card – while the rest is from unused balances.

TfL’s chief technology officer Shashi Verma said: “We’re committed to ensuring that our customers can get back the credit on their Oyster cards to use as they wish, including donating to charities that do such vital work across London.

“Customers can already donate their old Oyster cards to the Railway Children via charity boxes at Heathrow Airport, Kings Cross and Liverpool St.

“Over the last decade, this has helped raise more than £218,000 for the Railway Children, an international children’s charity who work with street children in India, East Africa and the UK.

“We are currently looking to expand the scheme with boxes at a number of additional sites across our network.”