Dowlers back 'no-win, no-fee' legal system
The family of Milly Dowler says planned changes to "no win, no fee" cases would have stopped them seeking compensation from News International.
A letter from the Dowlers urges David Cameron not to take "rights away from ordinary people so that large companies could print whatever they like".
The government says its plans are intended to prevent "spurious cases".
It is understood the Dowlers are to receive a £2m settlement over the hacking of the murdered girl's phone.
The deal is thought likely to also involve a personal donation of £1m to charity by company boss Rupert Murdoch.
A government spokesman said: "We are absolutely committed to ensuring that people can access the justice system, regardless of their financial situation, which is why we are committed to maintaining 'no-win, no-fee' arrangements."
But in the letter to the prime minister, the Dowler family said they were "lucky" they were able to claim under the current system, and without the insurance that the conditional fee agreement provided, they "would not have been able to start a case or even threaten it".
In March, Justice Secretary Ken Clarke announced plans to change "no win, no fee" cases in England and Wales.
He said lawyers would no longer be able to claim "success fees" from the losing side, and should instead receive a share of the damages.
The Dowlers said they understood the new law would "affect thousands of people who want to sue News International and other newspapers" and urged Mr Cameron not to change it.
"We had understood that you were on the side of the people, not the press. Please do not change the law so that the ability to sue the papers is lost.
"Although we may have received a sum that meant the cost of the insurance would have been affordable, most cases finish with settlements that do not cover the cost of insurance and so people will not bother," the letter said.
It went on: "We are sure that you do not want to go down in history as the prime minister who took rights away from ordinary people so that large companies could print whatever they like and break the law without being able to challenge them."
The Law Society, which has warned that the proposed changes seriously undermine access to justice, welcomed the Dowler family's letter.
Des Hudson, the society's chief executive, said: "After all they have been through, we welcome - and are humbled by - the intervention of the Dowler family in this debate.
"They have succeeded in making it clear to the prime minister that it is ordinary families with terrible life challenges that will be impacted the most. They will be the losers.
"As a society we need to protect them and their access to justice."
Levi Bellfield was jailed for life earlier this year for murdering 13-year-old Milly Dowler, who went missing in 2002.
In July, it emerged the girl's phone had been hacked for the News of the World.
The revelations that a private investigator had hacked into the phone after the murdered schoolgirl went missing and deleted messages, giving the family false hope that she was still alive, brought intense pressure on News International, which responded by shutting the paper down.
A Ministry of Justice spokesman said: "There are many deserving cases brought before the courts. But we have to stop the abuse of the system by others pursing excessive, costly and unnecessary cases. Under the current arrangements, innocent defendants can face enormous costs, which can discourage them from fighting cases. This simply isn't fair.
"So, in order to ensure that the no-win, no-fee cases continue to provide fair access to justice for all, we have to make changes.
"By balancing the costs more fairly between the claimant and defendant, these changes will ensure that claimants will still be able to bring deserving claims, and receive damages where they are due. Most importantly they will make the no-win, no-fee system sustainable for the future."