The 'Late in the Day' hitmaker insists fans should have time to''miss'' the band - who split up five years ago - before they even think about going on the road together again.
He said: ''The quick answer [to reforming] is 'no'.
''I think more time needs to pass, more water under the bridge. Don't you agree that people should miss us a bit more first?
''I'm at the start of this phase. I was in a band for 20 years but I've only been a solo artist for a couple of years, it's new to me.
''I wouldn't see the point right now or writing a song where people say, 'It's like having Supergrass back.' I don't think I could recreate that anyway.''
And the singer admits he doesn't want to listen to Supergrass' final album 'Release the Drones' and never felt excited about anyone hearing it.
He told NME magazine: ''I don't want to particularly hear it then, I don't know why I would now.
''I always used to love getting new tracks from the studio and then parking up at rehearsals, opening the boot and playing it really loud on the stereo. Being really proud of what you'd done.
''But the stuff we were working on, I didn't want to play it to anyone and that said a lot to me. It takes a lot of strength to confront that rather than doing whatever album and carrying on doing festivals every year and bringing the cash in playing the hits.''
American Thighs was released on this day in 1994.