Asbestos-related cancer sufferers are to receive up to £54,000 extra under new compensation rules.
The government said compensation will rise to match 100% of average civil claims, up from the current 80%.
Those diagnosed with asbestos-related mesothelioma from today will benefit from the payment increases.
The Diffuse Mesothelioma Payment Scheme has already paid out more than £19 million in its first 10 months helping hundreds of diffuse mesothelioma sufferers across the country unable to claim compensation as their employer or employer's liability insurer is untraceable.
Work and pensions minister Lord Freud said: "For years, many victims of this truly terrible disease have been failed by successive governments and the insurance industry.
"With this scheme we are continuing to help the many victims and families that mesothelioma has left without financial support.
"From today we are raising compensation payments to 100% of average civil claims. It is partly thanks to the success of the insurance industry in tracing liable insurers and employers that we are able to make these changes as part of our on-going commitment to support mesothelioma sufferers."
Due to the length of time between asbestos exposure and cancer diagnosis, many employers and their insurers no longer exist and so the liable successor organisations are often untraceable.
Steve Murphy, general secretary of the building workers' union Ucatt, said: "This is of course good news as the previous rules were unfair on mesothelioma victims who could not identify the company or insurer following their exposure to asbestos.
"However, the government continues to blow hot air into a long delayed, watered down scheme. This scheme is far weaker than had been intended by the previous Labour government which was consulting on these proposals prior to the general election in 2010.
"And it only covers mesothelioma victims and not workers who have developed other life changing illnesses as a result of being needlessly exposed to asbestos."
Adrian Budgen, head of asbestos-related disease at law firm Irwin Mitchell said: "We welcome the increase in the tariff as it means that victims of asbestos who cannot find the relevant insurer to bring a civil claim, will have access to a fund of last resort that now provides 100% of the average damages.
"However, by definition 'average' is less than many would receive and so for many it will still mean that they receive far less than they would receive if they received 100% of the damages that they would be entitled to if they could successfully purse a compensation claim
"Moreover, the fact remains that everyone diagnosed before today's changes, who is eligible for the scheme, will still only receive 80% of the average damages that they are entitled to."
Doug Jewell, of the Asbestos Victims Support Group, said: "We believe this help should be available to all those suffering because of exposure to asbestos.
"We believe the 200 people who have already received a payment under this scheme as well as people suffering from other diseases such as asbestosis should be included.
"We are concerned about the mention of new rules for the scheme which have been agreed with the insurance industry. This government has a history of doing deals in the dark at the expense of asbestos victims and we hope the minister will make clear what these changes are."
John McCluskey of the, GMB said: "We are greatly disappointment that those victims and their families who received 80% of the compensation since July 2014 will not be getting the missing 20%.
"Those victims who from February 2010, when the original consultation began, will receive nothing from this scheme.
"The government, while announcing how successful the scheme has been, continues to ignore suffering victims and their families in a purely unjust and arbitrary manner and GMB will continue to campaign on those who have been excluded or only partially compensated, from the scheme."
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