ROTTEN DEW

We’ll find out Monday what the official plans are for the Sex Pistols’ 20th anniversary celebration when the group gives a London press conference expected to announce a reunion tour this summer.

But the milestone unofficially kicked off recently with the first airing of a Mountain Dew TV commercial featuring none other than the singing of John Lydon, using his best Johnny Rotten voice for a punky version of “Route 66.”

“We had a version with a pretty cool but nondescript studio vocalist,” says Brad Shaw, spokesman for Pepsi, which makes Mountain Dew. “So we sat down with the folks at [ad agency] BBDO and said that we liked it, but it lacked the edge we want to have associated with Mountain Dew.”

So Lydon, who had never done a major commercial before, was approached and said yes.

Why did he do it?

“It was good fun,” says Ophire Finkenthal of Lydon’s management office, quoting the singer. “And a ton of money.”