Shears revealed in this month’s Uncut magazine that he was asked to perform guest vocals on the song, from the Floyd’s 1979 album ‘The Wall’, when Gilmour brought his solo tour to New York earlier this year.
Shears’ band famously covered the track in 2004 – it was their first UK hit single, and also appeared on their massive-selling eponymous debut album.
He said: “Pink Floyd helped us make it. We me them at Live8, and they were nice about it.”
But the singer was ultimately left disappointed by his hero.
He revealed: “Earlier this year, David Gilmour told my manager that he wanted me to sing ‘Comfortably Numb’ with him at Radio City Music Hall for two shows.
“So of course I’m emotionally fragile and weeping – a mess. I was so over the moon because I can sing the hell out of that song – I’ve been singing it for the latter half of my life.
“So I was practising it and doing my vocal exercises to it, but the day before the gig they decided not to have any guests. They canned me. Bastards! It was one of the worst things you can do to anybody. I kind of hate him for it.
“It was like taking candy away from a kid. My mom was getting on a plane to come and see me.”
Scissor Sisters release new album ‘Ta-Dah’ on September 18.
Uncut, featuring Kurt Cobain as its’ cover star, is on sale now at all good newsagents, priced £4.20. See Uncut.co.uk for more information.