During the general election Sir Ed’s main rivals included Rishi Sunak, Sir Keir Starmer and Nigel Farage.

Now, in his bid for chart-topping glory, he faces competition from the likes of Ed Sheeran, Tom Grennan and the 40th anniversary remake of Band Aid’s Do They Know It’s Christmas.

There are also other challengers in the field of charity singles. The Celebs (including ex-boxer Frank Bruno and The Chase’s Anne Hegarty) have released a cover of All You Need is Love to raise money for Great Ormond Street Hospital.

Reverend and The Makers are putting out Late Night Phonecall to support the Samaritans.

Although Sir Ed may be challenging some big names, there is a fine tradition of choirs making it to number one at Christmas – so he may have chosen a perfect musical coalition by teaming up with the Bath Philharmonia’s Young Carers’ Choir.

St Winifred’s School Choir famously kept John Lennon off the Christmas top slot in 1980 with There’s No-One Quite Like Grandma.

They were followed by the Military Wives in 2011 and the Lewisham and Greenwich NHS Choir in 2015.

But getting a Christmas number one is more complicated than it used to be, when the winner was simply the one which had sold the most singles.

These days the Official Charts Company uses a formula to combine CD and vinyl sales with downloads, streams and YouTube views, giving greater weight to actual sales (physical or downloaded).

As part of the formula, a song needs to be streamed 100 times on a paid-for subscription service to be worth the same as one download sale. For free video and audio streams, 600 plays are required.

But so many classic songs are played relentlessly at parties and on people’s playlists that those streams tot up quickly – which means the top of the festive charts tends to be dominated by the likes of Mariah Carey’s All I Want for Christmas and the Pogues and Kirsty MacColl with Fairytale of New York.

A year ago, Last Christmas by Wham! was the Christmas number one, 39 years after its release – and that song is the bookmakers’ clear favourite to do so again this year.

Wham! racked up 13.3 million streams a year ago to clinch that accolade – so if over the next few weeks we notice Sir Ed and his fellow Lib Dems frantically tapping at their phones, we will know the reason why.