The sums being charged by lawyers in no-win, no-fee cases are "nothing short of scandalous" and may have to be hit with tighter caps, Justice Secretary Jack Straw will say.
He will set out his determination to tighten up the system, the subject of a Government-ordered review since June, in his speech to the Labour Party conference in Manchester.
The system was introduced more than 10 years ago to allow people to hire lawyers for certain types of civil cases, such as personal injury claims.
Solicitors are only paid if they win the case, and are also entitled to a "success fee".
But there have been widespread worries that rogue firms seek clients to bring inappropriate cases, sometimes taking a large proportion of any winnings.
Mr Straw will also repeat his determination to force criminals carrying out community service to wear high-visibility jackets in a bid to increase public awareness.
He will tell delegates that the justice system should be seen as a public service - like health, education or the police - run in the interests of the law-abiding majority.
"Tough community sentences are effective punishments but the public must literally be able to see them taking place, see offenders paying back to the community," he will say.
A spokesman said the vests used would not be yellow, to avoid confusion with the police and other officials, but no decision had been taken yet on what colour would be used.
They would be clearly marked to identify the wearers as those doing community sentences, he said.
