The National Federation of Retail Newsagents has made an astonishing threat to launch a campaign for the removal of cover prices on newspapers, so that retailers could choose how much to charge. It follows a spate of price changes in the wake of the demise of the News of the World.

In the past fortnight, the Daily Mail has increased its cover price by 5p,but reduced newsagents' margin from 24.2% to 23.2%, meaning they will earn just 0.66p more per copy, rather than 1.21p losing out on 0.55p.

News International has moved Fabulous magazine, which was published in the News of the World, into the Saturday edition of The Sun without offering retailers extra money for delivering a heavier paper. And the Sunday Express has cut its cover price to £1, though it has since confirmed that margins will be maintained at the full cover price.

Kieran McDonnell, the new NFRN national president, said it was time newsagents took action.

"If the news industry wants a war, a war is what we will give them," he said. "I have put in train plans and actions for the NFRN to launch the most powerful and extensive public affairs and media campaign ever. If we are forced to campaign for the removal of cover prices, so be it."

He added that some newsagents had refused to deliver Fabulous magazine with the Saturday Sun and his message to publishers was "no pay, no play".

"We will be doing everything in our power to urge politicians and the competition authorities to refer this to the Competition Commission."

The Association of News Retailing said it would also push for a referral.