The 18-year-old singer from Whitburn, West Lothian, will perform on the Waverley Stage, Waverley Bridge, at around 10pm to get the annual street party under way.

It will top another amazing week for the youngster, who is expected to take the Christmas No1 spot with his debut single When You Believe.

The single is on course to sell around 250,000 copies by tomorrow – as much as the top ten combined, and enough to make it the fastest-selling single of the year.

The single was already at number one in the mid-week charts on the strength of downloads alone. The Rangers fan has also been invited to salute the crowds at Ibrox for the side's home tie against Motherwell on Boxing Day.