A Government body tried to hide information about the troubled Universal Credit IT project by failing to rate the scheme properly, it is claimed.
The Major Projects Authority (MPA) declined to give Universal Credit a proper rating of red, amber or green in an annual review of 199 Whitehall infrastructure projects published in May.
Instead, the Department for Work and Pensions' (DWP) controversial welfare reform programme was given its own 'reset' category.
This meant that while details such as the entire life cost of the other 198 projects was revealed, no such data was made public about the IT project to deliver Universal Credit, despite estimates it has written off millions of pounds so far.
The Public Accounts Committee (PAC) today claimed the MPA had given Universal Credit the reset rating in order to hide such details.
PAC chair Margaret Hodge MP said: "We are particularly concerned that the decision to award a 'reset' rating to the Universal Credit project may have been an attempt to keep information secret and prevent scrutiny.
"The MPA should also publish more information on each project, including the amount spent to date, even if this means reviewing the Government's transparency policy."
The PAC report details an MPA claim that the decision to give Universal Credit a reset rating was ultimately made by ministers. The DWP told CBR this was a Government-wide decision rather than one taken just by DWP minister Iain Duncan Smith.
"However, the MPA also told us that the decision to give this rating 'was a good thing for the project' as it allowed the project team a 'bit of breathing space to get themselves back on the front foot'," the PAC report added.
At the time, the DWP said the 'reset' rating reflected the decision in December 2013 to restart the project after it missed a flurry of rollout deadlines.
The National Audit Office (NAO) found it has wasted £40m so far, with another £91m to be written off by 2018. The watchdog will investigate the project again this autumn.
The DWP claims that 8,000 claimants are now registered on the Universal Credit IT system, but May saw the lowest uptake of the system for nearly a year, with just 540 new claimants registering.
PAC believes the MPA needs more power to make government projects more accountable.
It said: "The MPA often has to rely on personal credibility and informal influence, rather than having formal mechanisms, to get its voice heard in its work with departments.
"This lack of formal powers reduces the influence of the MPA with the Treasury and with departments, limiting its ability to drive improvements in project management."
A DWP spokesman said: "This is a historical rating that reflects the decision to reset the programme in 2013. Now this reset has taken place, future MPA reports will give a full delivery assessment of Universal Credit.
"In terms of transparency, Universal Credit has had the most reviews and the highest number of reports written about it out of the 44 major projects.
"The reality is that Universal Credit is already making work pay as we roll it out in a careful and controlled way. In fact it is already transforming people's lives and is available in a growing number of areas, including 39 Jobcentres, and we have started taking claims from couples too. By the end of this year, around 1 in 8 Jobcentres will offer Universal Credit."