Kerri-Anne Kennerley's On-Air Revenge For The Chaser's Opera House Prank

Studio 10 host Kerri-Anne Kennerley decided to go tit-for-tat with The Chaser's Charles Firth on Tuesday morning, displaying the comedian's personal phone number in retaliation for a prank played on 2GB shock jock Alan Jones.

Overnight, The Chaser projected an advertisement on the sails of the Sydney Opera House, which included Jones' personal phone number.

"I think it's very clever what you did for your show, but the number?" said Kennerley. "I think that was too far."

Firth admitted that the team had a big internal debate about the idea.

"Some people thought it was a good idea, other people thought it was a bit of a horrible thing to do to a person, but he's been horrible to so many women," he said.

READ MORE: The Chaser Project Advertising Sign On Opera House

"Oh what absolute rubbish," Kennerley replied, conceding that Jones has a "temper", but arguing that his treatment of Opera House CEO Louise Herron was "nothing to do with being a woman."

Things took a turn when Kennerley demanded Firth hand over his own phone number -- and he agreed.

"Are you serious?" host Sarah Harris asked, as Kennerley wrote down Firth's phone number on a piece of paper.

"Yeah, you can give me a call if you like," he joked. Harris put the number in her own phone.

Kennerley held up Firth's phone number in triumph as his mobile began to ring.

The Chaser's Charles Firth gets a call on-air after Kerri-Anne Kennerly held up his personal phone number. Photo: Studio 10.

"Is that you?" he asked Harris, answering the phone. But it wasn't. "Oh, I've got lots!" said Firth, showing his incoming calls to the camera.

"One's from '666'. Oh, I think that's Alan Jones, actually."

Meanwhile, Jones issued an apology to Herron on his Tuesday morning program, saying that he used some words that "in hindsight I now most regret hearing".

"So to Louise and those people who've been offended, I apologise."

It comes as the Change.org petition to "defend our Opera House" hits a quarter of a million people -- and counting.

READ MORE: Opera House Petition Delivered, Alan Jones Apologises And An On-Air Spat

Just hours earlier, petition starter Mike Woodcock delivered a heavy stack of paper to NSW Parliament, with Greens MP Jenny Leong accompanying him inside the building to get it "as far as it could go".

"I felt pretty pissed off about the [Alan Jones interview], and I figured a lot of other people might feel the same way," he said.

Contact the author: abrucesmith@networkten.com.au

Lead photo: Studio 10.