Uncertainty over when the computer systems needed to implement the government’s flagship Universal Credit benefit reform programme – implementation deadline could be missed, MPs warned.

The work and pensions select committee said the rollout of the reform, which has been delayed due to problems with the IT system, was happening at ‘a snail’s pace’.

The plan to merge six benefits into one payment by 2017 originally set a target for one million people to have been switched to Universal Credit by the end of the year.

However, committee chair Dame Anne Begg highlighted the system would not be open to all new claimants across Britain until 2016, and the bulk of existing claimants will not move over to Universal Credit until 2017.‘Only 4,280 people were claiming Universal Credit by December 2013 and the majority of these claims were of the simplest nature,’ she added.

‘By comparison, in the same month, 1.22 million people were claiming Jobseekers’ Allowance. This demonstrates the scale of the challenge still facing the government in trying to implement Universal Credit by 2017.

More than 1 million people should have been moved on to the government’s new Universal Credit benefit by April 2014, Work and Pensions Secretary Iain Duncan Smith has set out the government’s timetable to move 12 million claimants on to the credit, which will combine most existing benefits into one payment. The government says that the changes will simplify the system to make work pay and combat poverty.

All claimants will be receiving the new benefit by 2017, after the completion of a three-stage transfer. It began in October 2013, new claimants were to receive Universal Credit in place of Jobseeker’s Allowance, Employment Support Allowance, Housing Benefit, Working Tax Credit and Child Tax Credit.

An estimated 500,000 existing claimants, their partners and dependants were expected to move on to the new credit between then and April 2014 as and when their circumstances change, such as when they find work or a child is born.

From April 2014, a second transfer will take place, with priority being given to households that the government says will gain the most from the transition. These include people receiving Working Tax Credit who work a few hours a week and would currently lose more in benefit that they gain in income from working extra hours. The Universal Credit aims to make work pay by tapering the withdrawal of benefits and extending financial support for childcare.

In the final phase, which will begin at the end of 2015 and run through to the end of 2017, around 3 million households will transfer in stages based on local authority boundaries.