Tony Blair moved to bring an end to his rockiest 24 hours of the election campaign by saying he had spoken to the deputy prime minister who regretted the incident.
" Of course he regrets the incident ever happened but he felt a blow on the side of his head and acted instinctively "
Mr Prescott, who was hit with an egg, reacted by punching the protester during a visit to North Wales.
At Labour's morning news conference Mr Blair said: "Of course he regrets the incident ever happened but he felt a blow on the side of his head and acted instinctively."
"I think it is important in these next three weeks that we have a campaign in which there is a genuine dialogue and debate with people.
Taken to task
"When I go round the country and talk to people there are real and serious issues in this campaign. It is those real and serious issues that in the end should determine the future of the country."
The prime minister also referred to another incident when he was taken to task by the partner of a cancer patient during a visit to a Birmingham hospital.
He said it underlined the clear choice between Labour and the Conservatives over future investment in the NHS.
The plight of Keith Sedgwick, 48, who is being treated for non-Hodgkin's lymphoma, underlined "precisely the case for carrying on the investment we have put in and are putting in".
"We need more beds, doctors, nurses and equipment and that's precisely what we promised in our manifesto."
The choice for electors was a strong economy with investment in schools, hospitals and transport under Labour or "plans for £8bn or it now appears £20bn" in Tory cuts, Mr Blair said.
Mr Blair had warm words for Mr Prescott saying he was "lucky" to have such a "loyal" and "decent" deputy.
"You could not wish for a deputy more loyal, more true or more decent and he cares about his country, he cares passionately about his politics and John is John - but I tell you I am lucky to have him as a deputy," he said.
"I think what is important is that we get back to the issues."
But Mr Blair refused to be drawn into the issue of whether Mr Prescott would keep his job as the boss of the Department of the Environment, Transport and the Regions in the event of a Labour win at the election.
There were lighter moments during the news conference.
At one point Mr Blair said he was going to take his jacket off and hand over to Education and Employment Secretary David Blunkett who quipped: "I was quite worried when he said that."
And Chancellor Gordon Brown, who presided over the news conference, immediately referred a question on being pelted by fruit to the prime minister.
"This is a question I'll put to Tony Blair. I have not been pelted by tomatoes - yet."
To which Mr Blair said: "We'll have to arrange something, Gordon."