Prince William jokes about the prospect of Kate having twins

Prince William attended Centrepoint's annual awards ceremony at Kensington Palace last night. Photo / Getty

He's set to become a father-of-three when the Duchess of Cambridge gives birth in April, but Prince William has admitted he's relieved Kate is not expecting twins.

According to Hello! magazine William joked with Raymond Stoner, boss of Anston Properties, at last night's Centrepoint awards about the new arrival and admitted he's getting as much sleep as possible in the meantime.

When Mr Stoner suggested he could save time by having twins, William replied: 'Twins? I think my mental health would be tested with twins, reports Daily Mail.

"Two is fine, I don't know how I'm going to cope with three, I'm going to be permanently tired."

Last night's awards honoured the achievements of young people who have overcome homelessness at a reception at Kensington Palace, attended by celebrity supporters of the charity, including actress Emilia Clarke, TV presenter Jonathan Ross, and Downton Abbey creator Julian Fellowes.

The Centrepoint awards, which are being held for the third time, recognises young people for their efforts in personal development, sport and education.

The organisation, which turns 50 next year, provides physical and mental health support to 16 to 25 year-olds to people who are homeless.

William and Kate are set to welcome their third child in April, and the Duke admits he's been catching up on as much sleep as possible ahead of the birth. Photo / File

William has long been a supporter of the charity, officially becoming a patron in 2005.

His mother Princess Diana was also a patron of Centrepoint before she died.

Last year, William helped launch a new helpline for the charity, which helps young people with advice and support on housing, as well as related issues such as mental health, relationships, money and work.

It has been a busy day for William, who visited the Ark Burlington Danes Academy in Shepherd's Bush, west London, this morning along with rapper Professor Green.

William joked that he'd struggle to cope with twins as he's already nervous about having three young children to look after. Photo / Getty

Speaking to pupils at the school, he revealed his worry for young girls who feel pressure to emulate the airbrushed pictures they see online.

The prince said: "I worry for you girls. The touched up pictures are not real.

"Don't try to recreate them or think that's what you've got to aim for. There's a lot of fakeness online so don't worry about that."

He added: "For your mental health, get outside, come away from the screen."

William, who has daughter Princess Charlotte, two, was taking part in a discussion about how to stay safe and happy online.