The six-week waiting time for universal credit should be cut and be a maximum of one month, MPs say.
The Work and Pensions Select Committee said the six-week wait before claimants receive their first payment was causing “acute financial difficulty”.
It said reducing the delay – designed to mimic waiting for a first pay cheque for a new job – would remove a “major obstacle” to the policy’s success.
Theresa May has said the government was listening and was making changes.
At Wednesday’s Prime Minister’s Questions, Mrs May defended the concept of universal credit, which she said was a “simpler” system that “makes sure work pays”.
Universal credit, which rolls six working-age benefits into a single payment, is designed to make the system simpler and ensure no-one faces a situation where they would be better off claiming benefits than working.
But it has faced a backlash from some MPs, who fear payment delays risk pushing families into destitution.
Conservative committee member Heidi Allen said: “Despite the clear support for universal credit, there is cross-party recognition that the six-week wait does not honour the original intentions of the system.
“To truly represent the world of work, the payment cycle must mirror how the majority of people are paid i.e. monthly.”
The cross-party committee said advance payments could “mitigate some of the unwelcome consequences of the current design of universal credit, but they do not address their underlying foundations”.
Its report concluded: “The baked-in six-week wait for the first payment in universal credit is a major obstacle to the success of the policy.
“In areas where the full service has rolled out, evidence compellingly links it to an increase in acute financial difficulty.”
Work and pensions committee chairman Frank Field said the waiting period for the first payment was “cruel”.
“Such a long wait bears no relation to anyone’s working life and the terrible hardship it has been proven to cause actually makes it more difficult for people to find work,” the Labour MP said.
Universal credit has been introduced in stages to different groups of claimants over the past four years, with about 610,000 people now receiving it.
Almost a quarter of all claimants have had to wait more than six weeks to receive their first payment in full because of errors and problems evidencing claims.
But the government recently approved a major extension of the programme to a further 45 job centres across the country, with another 50 to be added each month.