Kenyan MPs have voted to award themselves a $22,000 bonus each at the end of their five-year term in December despite a wave of public condemnation.
The protesters say MPs do not deserve such a huge pay-off
The move has been condemned by lawyers and human rights activists who say it is "highly immoral". They held a protest against the proposal in July.
The bill also legalises huge perks that ministers have been receiving.
MPs had originally wanted a bonus of $98,000 each but the finance minister said the country could not afford this.
Kenya's 222 MPs already earn more than $10,000 a month in salaries and expenses, much of which is tax-free, in a country where most people live on less than $1 a day.
Many Kenyans see MPs as lazy and self-interested, who often skip parliamentary sessions unless it concerns a pay rise for themselves.
"It is highly immoral and even if it is not illegal, further research is needed to establish what the taxpayer can do to stop MPs from enriching themselves," said Kenyan National Commission on Human Rights chairman Maina Kiai, according to the Nairobi Star newspaper.
MP's ANNUAL SALARY
South Africa: $53,753
Source: Commonwealth Parliamentary Association, 2005
Mwalimu Mate from the anti-corruption group, Mars, said he was considering taking legal action over the issue.
"There will be a programme of action, which will include public protests," he told the BBC's Focus on Africa programme.
"We will also make this an election issue, in that civil society will campaign against incumbents because of this greedy action."
Elections are due in December, with President Mwai Kibaki expected to seek re-election.