Francis Maude told ITV News that the initial implementation of Iain Duncan Smith's Universal Credit system had been "pretty lamentable".
Work and Pensions Secretary Iain Duncan Smith has denied claims that his welfare reform programme is a "debacle".
Minister dismisses claims he attempted to pin the blame for "shocking" failures in his flagship welfare reform on his senior official.
The Government's Universal Credit programme will roll out across more JobCentres from the beginning of next week.
The new payment, which combines six means-tested benefits and tax credits into one benefit, will be expanded across the north-west of England.
The latest figures show that up to March of this year, 6,550 people had claimed Universal Credit.
Iain Duncan Smith's universal credit scheme has been given a unique classification in an annual progress report issued by the Government.
Although many of the projects are listed as being "exempt" from publishing a green, red or amber risk (most citing the Freedom of Information Act as the reason), the universal credit scheme is the only one to be listed as "Reset".
– Major Projects Authority annual report 2014
During 2013, the Programme was reset, culminating in the revised plans announced on 5 December 2013.
The lack of transparency was highlighted by The Independent, which claimed the Major Project Authority had rated universal credit as “red”, signifying that it is “unachievable within reasonable timescales and to a reasonable budget without urgent remedial action”.
Iain Duncan Smith has successfully prevented the publication of a "damning" report into his universal credit scheme, according to The Independent.
As part of its drive to increase transparency, the Government published the progress of around 200 projects today, rating each on a risk scale of green, red or amber.
But today's Independent front page claims universal credit was "the only project not to get a rating".
The progress report represented £400bn of public spending.
The Government dismissed claims it had deliberately obstructed an inquiry into the botched roll out of their flagship Universal Credit reforms.
A spokesman for the Department of Work and Pensions said:
– Department of Work and Pensions
Universal Credit and its IT systems are very clearly working well, with claimants receiving the new benefit and moving into work.
We deliberately started in a slow, controlled and safe way, which the Committee itself has long recommended, so we can expand Universal Credit securely to more people.
Universal Credit is on track and we will start expanding it to other Jobcentres from this summer.
We have made our plans to roll out Universal Credit very clear with regular updates.
MPs have expressed scepticism about the Government's ability to deliver wide-ranging benefit reforms on time.
The Work and Pensions Select Committee said Iain Duncan-Smith's department had worked at "a snail's pace" and failed to be open and transparent with their investigation.
– The Work and Pensions Select Committee
Whilst it is right to ensure that the system works properly before extending it, there is a difference between cautious progress and a snail's pace.
Given the excruciatingly slow pace of roll-out to date, it is hard to see how the most recent implementation timetable can be met.
Effective select committee scrutiny depends on the provision of accurate, timely and detailed information by government departments.
DWP has not always provided this to the committee in the case of Universal Credit.
The Government has been accused of "hampering" an inquiry which found tens of millions of pounds had been wasted on flagship Universal Credit reforms.
The Work and Pensions Select Committee said there remained "worrying uncertainty" about the computer system being used to usher in the new single payment for unemployed or low income families.
The committee suggested the Department for Work and Pensions (DWP) had not been cooperative during the investigation and urged them to be "clear and frank" about implications of delays.
Computer problems meant that £40 million spent on software has had to be written off because it is of no further use, and a further £90 million has been spent on IT with a useful life of only five years, said the committee.
Universal Credit will replace six benefits, including jobseeker's allowance, income support, child tax credit and housing benefit, but a national roll out has been delayed.
In response to Cabinet Office minister Francis Maude's admission that the implementation of the Universal Credit system has been "pretty lamentable", the Department for Work and Pensions has told ITV News Iain Duncan Smith has "not shied away from any tough decisions" over the policy:
DWP spox says Iain Duncan Smith has not shied away from any tough decisions in terms of Universal Credit development and implementation.
Labour's shadow work and pension secretary Rachel Reeves has asked "when will the PM and IDS [Iain Duncan Smith] get a grip" on Universal Credit, after Cabinet Office minister Francis Maude admitted to ITV News that its implementation had been "pretty lamentable" so far:
Even cabinet ministers are now admitting Universal Credit is a shambles. When will PM and IDS get a grip? http://t.co/atKNnM5yU7