Labour MP Frank Field, chair of the Commons work and pensions committee, has urged the government to keep the universal credit helpline open during the Christmas break for claimants at risk of spending the festive season without money.

From 23 December to 1 January, job centre offices and the Universal Credit helpline are only fully operational on 28 and 29 December in England, Wales and Scotland. The helpline will open on 27 December in Scotland to to deal with payment enquiries from claimants from all nations.

The Department for Work and Pensions (DWP) said it was normal for services to close at the weekend and during bank holidays, and said millions of universal credit payments would be brought forward in time for the Christmas break.

In a letter to Theresa May, Field wrote: “Any of my constituents making a claim for universal credit this week are due, if the system works as planned, to receive their first payment a few days either side of Christmas. However, if a problem arrises or an error is made during the process of their claim, that money will not arrive and my constituents will be without an income over Christmas. For my poorest constituents this could trigger a period without food, heat or light.”

“Usually it is the universal credit helpline that provides a vital layer of protection to those claimants who are without money and wish to enquire about the status of their claim so it can be resolved and money paid,” it continued.

“The thought of the chaos this will cause to the lives of some of my poorest constituents, and those across the country, is a hugely troubling one,” the letter read.

The universal credit system combines six benefits into one online-only system, aiming to simplify the benefits system and increase incentives for people to work.

The new system has suffered from problems with delays and implementation, pushing some claimants into rent arrears, food bank use and mental distress.

A DWP spokesperson said: “Just like organisations across the country, our offices are closed on public holidays but every year we bring forward over 20m payments worth more than £4bn to benefit claimants.

“Phone lines are open on 27 December to help people with any urgent payment-related enquiries, and open as usual every other day around the Christmas period.”