A five-week wait for Universal Credit has been a major factor in pushing some claimants into rent arrears, the government's own research has found.
Universal Credit merges six existing benefits into one and is being introduced gradually across the UK.
Citizens Advice has criticised the initial wait for payments, calling for a suspension in the roll-out.
But the government said monthly payments reflected the way many working people were paid.
Universal Credit combines existing benefits such as tax credits, housing benefit, income support, Jobseeker's Allowance, and employment and support allowance. By 2022, more than seven million households will receive Universal Credit - at least half of which will be in work.
A major rollout of the scheme begins soon, following a series of delays. The system was originally scheduled to be fully in place this year.
New figures published by the Department for Work and Pensions showed that around one in four new claimants waited longer than six weeks to be paid.
Of those Universal Credit claimants who fell into arrears on their rent, the majority said it was the first time they had fallen behind on their payments in their current accommodation.
Earlier in the week, Citizens Advice said its research showed that those under the Universal Credit system were more likely to struggle with priority debts.
The publications, ahead of a major acceleration in the roll-out of Universal Credit, has prompted debate among MPs and calls for a rethink.
Labour said the system was in "total disarray", while Tory MP Heidi Allen told the BBC that the government "should slow down a little bit and get it right".
Work and Pensions Secretary David Gauke said Universal Credit offered an unprecedented level of personalised support and he was committed to ensuring payments were made on time.
"We have been rolling out Universal Credit in a careful, safe and controlled way, allowing us to make improvements as we go," he said.
"We want to ensure that payments are made on time and that people can take up all the extra support that didn't exist under the previous system."