Kim Howells, Labour's competition spokesman, said yesterday that if a company tried to force a competitor out of business by undercutting it with uneconomic prices, action should be taken to put the boot on the other foot with big penalties that could force the predator to the wall.
Labour's tough new line is the strongest evidence yet that Tony Blair has done no deal with Rupert Murdoch to win the backing of his tabloid, the Sun. Mr Murdoch's cut-price edition of the Monday Times, which sells for a loss-making 10p, would be one of the first targets of Labour's promised purge.
Labour's pledge could also hit the slicing of bread prices by supermarkets, petrol station price wars, computer chips and bus fares where big companies are trying to drive small-scale competitors out of business.
Mr Howells told The Independent: "We need to move as quickly as possible to introduce some of the more important measures on competition policy. If there is a much more prohibitive regime, then companies will realise that they are taking great risks if they attempt to use predatory pricing as an illegal means of destroying their opponents and competitors."
Using bus companies as an illustration, he said: "The Office of Fair Trading should have beefed-up powers to see that if a company was clearly charging fares that were uncompetitive, in order to drive another company out of business, then it would have the power to step in and fine it very heavily - so much so that the predator could find itself in danger."
Following this week's agreement on Labour's manifesto, finalising it in time for publication next week, Margaret Beckett, Labour's Trade and Industry spokeswoman, said: "We will make as early changes in competition policy as we can."
She said there was a widespread consensus on the action that needed to be taken against restrictive practices.
"We were expecting the Government to bring forward proposals. We were not expecting there to be great disagreement, but as usual the Government ran away from anything constructive," she said.
Mr Howells said there was no question of a Labour government using regulation as a backdoor substitute for public ownership. Those days were gone. "There is not a single area of new Labour policies that has undergone more revolutionary change than this one," he said.
"What we have to do is to construct regulatory frameworks which encourage innovation and entrepreneurial spirit constantly to meet an increasingly global challenge."
The Tory government has repeatedly promised action on competition but has for years procrastinated on legislation.
The last Labour government published a Green Paper on restrictive practices in 1979.
The Conservatives published a Green Paper in 1988, followed by a White Paper containing legislative proposals in 1989.
Unusually, the Government then took a step backwards, with another Green Paper in 1992, followed by a statement of intent. A draft Bill last August failed to make the Queen's Speech.
The Labour Party is to hold a series of "New Labour Shows", featuring political speeches, satire, comperes and music, for new party members during their election campaign, it was revealed yesterday, writes Jo Jo Moyes.
The shows, the first of which will take place in Redditch next week, will be staged in theatres and may be "Evangelical" in tone, according to a spokesman.
The Deputy Labour Leader John Prescott revealed details of the shows as he prepared to travel to the Birds Eye Fish factory in Cleethorpes yesterday morning, during the second week of his "Prescott's Express" tour of 90 key regional seats.
Mr Prescott said he would be speaking at six of the eight planned events, along with key party figures such as Shadow Chancellor Gordon Brown, Robin Cook and Mrs Beckett. It was not clear whether Mr Blair would also be taking part.
Based on Labour's former "Rolling Road" show, Mr Prescott said the events would take place in the evening and feature comperes such as Richard Wilson, the actor best known for his role in the comedy series One Foot In The Grave.