Plans to extend the introduction of universal credit (UC), which combines individual benefits into one single monthly payment, could have catastrophic consequences, the charity said.

There are still numerous problems with the system, including a long wait for recipients for the first payment, it added.

The charity, which offers advice to those in debt, renewed its calls for the government to halt its plans.

The Department for Work and Pensions has planned to increase the introduction of the benefit from five to 50 areas a month from October.

Having looked at 50,000 cases of people in debt, the charity found that more than a third of people on UC were waiting more than six weeks for a first payment, and one in 10 were waiting more than 10 weeks.

The majority had priority debts such as rent or council tax, putting them at greater risk of eviction, visits from bailiffs, being cut off from energy supplies and even imprisonment.

People on UC were also typically left with as little as £3 a month to pay off debts, while two in five had nothing left to pay creditors because essential living costs exceeded their income.

Further issues stemmed from insecure employment such as zero-hours contracts causing a fluctuating income, money being taken from UC payments for rent arrears or tax credit overpayments and administration errors by jobcentre workers or the UC team.

Citizens Advice pointed out that by 2022 more than seven million households will receive UC with more than half of them in work.

Shadow work and pensions secretary Debbie Abrahams said: “The government’s failure to meet their own commitment to ensuring people receive support within six weeks will lead to mounting debt and arrears, pushing families deeper into poverty.

“The Tories must halt the roll-out of the programme until urgent reform and redesign of universal credit has taken place.”

The National Audit Office announced last week that it is launching an inquiry into the effectiveness of UC after the Residential Landlords Association stated concerns that changes would lead to rent arrears, higher levels of evictions and unwillingness from landlords to house benefit claimants.