The 'Shockwave' hitmaker also denied Noel's claim there was "a lot of cocaine involved" in the feud, as he insists he never partook in the illegal substance whilst spending time with Blur.
He added: "And I've never done cocaine with any of that lot out of blue Rkid you and your witch need to up yer game (sic)"
In Noel's original comments, the 52-year-old rocker said: "Liam and Damon were sh***ing the same bird and there was a lot of cocaine involved. That's where the germ of it grew from."
And Alan McGee - who signed Oasis to his Creation Records label - has backed up Noel's claims in quotes reportedly taken from a new book.
He said: "There was a situation with a girl. That created the Britpop war. Damon sh***ed somebody close to Liam. It was one of many women Damon was friendly with.
"Then he got off with her for a one-night stand and that created the rub. They were all goading each other after that."
Liam has also responded to Alan's claims, insisting he will "get slapped" if he doesn't "keep [his] f***ing mouth shut".
He tweeted: "And as for you McGee you f***ing wasp keep your f***ing mouth shout about me or you'll get slapped as you were LG x (sic)"