Record shops across the UK have reported a buying frenzy of Will Young's debut single.
Managers at HMV and Virgin Megastores say the double-A-side is "flying off the shelves."
It looks set to be the fastest-selling debut single in British history.
The single coupling Evergreen and Anything Is Possible is almost certain to go straight to number one when the UK singles chart is unveiled on Sunday.
A spokesman for HMV said: It 's been flying off the shelves. Customers were milling around before stores opened and many have been making multiple purchases.
"One lady at HMV in Dundee started queuing before 7am, so a few fans have been going to some quite extreme lengths. There's been 1.2 million copies ordered so we're stocked up to the eyeballs. I doubt we'll sell out."
A spokesman for Virgin Megastores said: "It looks like this is set to be the biggest single of the year with the stock literally flying off the shelves.
"Everyone from middle-aged women to young men and kids buying more than one copy of the single each.
"It's gone bonkers. We've already had reports from some stores that they are going to sell out by the end of the day, right the way through from Glasgow to Hastings."
Virgin Megastores placed its biggest-ever order for a single using the sales of Hear'Say's debut single within its first two weeks as a gauge.