Video: Brawling on the street in spin-doctor row

Iain Dale, of Biteback Publishing, was involved in a scuffle with the man on the Brighton seafront in an effort to stop him appearing on screen behind McBride during a series of media interviews.

The protester – a familiar face outside party conferences, regularly appearing with banners opposing smoking or nuclear energy – managed to get himself in shot as Mr McBride spoke on breakfast television.

But Mr Dale decided to take action, grabbing the man's rucksack and physically hauling him out of the way of the cameras, and the pair grappled on the pavement as Mr McBride's interview continued.

The barking of the protester's dog – which eagerly joined in the commotion – could be heard by TV viewers as the struggle continued.

But the terrier – carrying placards reading 'No Nukes' on its back – failed to live up to the loyalty expected from dogs, jumping up and biting its owner on the rear.

The protester doggedly attempted to make the best of the situation, holding up his banner reading 'No Nukes – Radio Active Dust Cancer Epidemic' to photographers who were busy recording the scrap.

After a few moments, the pair separated and dusted themselves down, and the protester went back to trying to edge his way into view of the cameras.

Writing on his blog, Mr Dale joked: "I knew I shouldn't have had three Weetabix this morning." He added he had seen the man holding his placard behind Mr McBride and distracting from his interview.

"I did what any self-respecting publisher would do – got out of the car, ran across, got him in an armlock and pulled him out of the shot. He started resisting and we ended up in an unseemly tumble on the ground.

"I was conscious of the photographers and other cameramen who were present filming the whole thing, but I was determined this idiot shouldn't disrupt what was an important interview for my author.

"I am someone who runs a mile from any form of physical confrontation normally, but I never understand why broadcasters seem to accept without question that someone with a placard or a loud voice should disrupt this sort of interview.

"Anyone who has seen the pictures can see that there was no real violence. I certainly didn't hurt the guy. He threw a punch at me but missed, and the only injury was when the man's dog bit him."

He added: "In some ways I have committed the cardinal sin of becoming the story myself, rather than my author, and I regret that. But do I regret that I stepped in to protect my author? No, I do not."

The protester was Stuart Holmes, a pensioner from Manchester, who is in his 30th year as a fixture outside party conferences.