A group of 30 Opposition MPs is urging the Government to shelve the introduction of the new benefit in about 50 new areas until next year, to avoid festive hardship.
Universal credit is meant to streamline the social security system but has been plagued by problems in trial areas where it is already up and running.
Citizens Advice has warned that claimants are being plunged into debt, with four in 10 people having to wait more than six weeks to receive their first payment.
Now the Labour MPs, from areas where the shake-up is due to be introduced this autumn, have written to David Gauke, the Work and Pensions Secretary, calling for delay.
“There is a real worry that the introduction of universal credit, at this time, will cause extreme hardship for many people in vulnerable situations, exacerbated by the financial burdens of the festive period,” they state.
“Evidence from other parts of the country where UC has been introduced already shows that it is far from the efficient system trialled.
“In many cases, recipients have had to wait seven weeks for payment of the benefits. This puts an incredible strain on individuals and we have seen, in other areas, an increased use of food parcels during this period.”
The letter also highlighted the removal of a severe disability premium and the difficulties people had repaying crisis loans of £150 in three £50 lump sums.
The MPs wrote: “The current timetable will cause our residents severe hardship over the months which are most financially difficult.
“We urge that you do not roll this system out in November and December, but look to a date later in 2018.”
The Labour MPs are led by newly-elected Laura Pidcock and include Kate Osamor, a shadow cabinet minister, Stella Creasy, Alison McGovern, John Mann, Jon Cruddas and John Cryer.
Their plea is the latest in a long line of warnings that universal credit is not ready for wider introduction.
The benefit is paid to about 530,000 people in trial areas, but this number will rise sharply in the autumn, if the planned expansion goes ahead.
In June, Citizens Advice’s survey of 800 people in pilot areas found that 57 per cent were having to borrow money to get by as they awaited their first payment.
The report also detailed problems with the online application system and long waits, often more than 30 minutes, to get help over the phone.
In February, David Freud, a former welfare minister, admitted to MPs that administrative problems were causing about one in four low-income tenants to run up rent arrears, putting them at risk of eviction.
But a DWP spokeswoman said: “We are rolling out Universal Credit in a gradual, safe and secure way and the majority of people are managing their budgets well.
“The best way to help people improve their lives is to help them into work, and under Universal Credit people are moving into work faster and staying in work longer than under the old system.”
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies