Survivors of the 7 July London bombings and relatives of those killed delivered a 10,000-signature petition to Downing Street demanding better pay outs.
Garri Holness lost part of his leg in the 7 July bombings
Many say they had no financial help and described the compensation scheme as slow, inadequate and insulting.
Government rules mean bereaved families get £11,000 and the maximum for the seriously injured is £500,000.
But questions have been raised at the Home Office about whether to re-examine compensation rules for victims.
A consultation paper is to be published on help for victims, which will look at compensation.
After the 11 September attacks, families of those killed received about $2m (£1.1m) from the US Government.
So far the Criminal Injuries Compensation Authority has received 258 applications for compensation and has paid out 53 awards totalling more than £750,000.
But London bombing victims want the government to abolish the ceiling on compensation, as well as immediate help for victims and guaranteed long-term financial security for survivors.
'Out of order'
The "What About The Victims?" campaign was launched last month by The News of the World newspaper.
Garri Holness, 37, from Streatham, south London, who had part of his left leg amputated after being caught in the Piccadilly Line blast, said imposing a cap on compensation was "out of order".
"It feels horrible, the fact that I have had to get in a wheelchair and knock on Number 10 Downing Street to let them know about this," he said.
"No amount of money is going to give me back my leg so I cannot put a figure on compensation, but I am going to need financial security for the rest of my life."
Stacy Beer, 24, whose brother Phil, 22, from Borehamwood, Hertfordshire, died in the Piccadilly Line blast, said she was angry the families had been left to take action themselves.
"You cannot put a price on a person's life. No amount of money will bring them back, but money will help the survivors - it will help them rebuild their lives."
Earlier this week Prime Minister Tony Blair said a new scheme could be established to pay compensation to UK victims of terrorism.