In between tending the sick, Dr Harriet Nerva has turned music promoter, launching a social media campaign to get a Christmas hit.

Bridge Over You, a mash-up of Coldplay's Fix You and Simon & Garfunkel's Bridge Over Troubled Water, sung by the Lewisham and Greenwich NHS Choir (right), was runner-up on Gareth Malone's TV show Sing While You Work in 2013.

Now Cambridge-based Ms Nerva, 26, who represents junior doctors on a British Medical Association committee, wants people to buy the song to support the work of the NHS. "We are facing a harsh winter and feel the government has let us down," she said.

But if you want to back her bid to make it to No 1, she said, delay buying it "until the week before Christmas".