Kermit the Frog and Miss Piggy, who have been on-again, off-again over the years, have finally called time on their relationship.

But they’re vowing to remain professional on their new prime-time comedy The Muppets, premiering in the US in September on ABC.

Kermit and Miss Piggy split
(Richard Shotwell/Invision)

The pair confirmed their break-up at a biannual ABC panel for TV critics. A statement followed on their official Twitter accounts.

“People change. So do frogs and pigs … We were together for a long, long time and it’s personal,” Kermit said.

Screen star Alan Cumming was one of a number of famous faces who expressed his dismay at the news.

Fashion designer Marc Jacobs was also upset.

Kermit also acknowledged starting a new relationship, after actress Emmy Rossum suggested they could be a new couple.

The Muppets is a mockumentary-style look at Kermit, Piggy, Fozzie and the gang as they produce a late-night talk show for Miss Piggy called Up Late With Miss Piggy.

The former couple sat at Tuesday’s panel with co-executive producers Bill Prady and Bob Kushell.

Prady said the idea to bring The Muppets back to prime time came up eight years ago but the timing wasn’t right. He took the idea to ABC in February. He said the network wanted a pilot right away so he created a 10-minute presentation.

(Richard Shotwell/Invision)
(Richard Shotwell/Invision)

He hoped to take the summer to do more, but ABC ordered the show to series with an autumn premiere.

“There’s no part of me whatsoever that did not want to wait,” Prady said. “This went very fast and, you know, it makes the work harder.”

Although there will be musical guests, the show will be less like a variety show and more like The Office or Modern Family.

This is a new direction for The Muppets, but Kushell said he believes it will appeal to both old and new fans.

“Anybody that hasn’t seen The Muppets in the past will see this whole new world and it will seem fresh and original and new to them, and anybody that has grown up with that will have that nostalgic feel but also their minds blown by the way we are doing the show,” he said.