A flawed computer system to recruit soldiers for the Ministry of Defence (MoD) could end up costing £50m more than originally planned, according to leaked documents.

The Recruitment Partnering Project – a £1.3bn service designed to allow up to 1,000 soldiers to return to frontline duty – is underpinned by a hosting platform that is being built by Atlas, a consortium of IT vendors comprising HP, Fujitsu, CGI and Cassidian.

Despite the government’s attempt to save money by laying off soldiers and hiring reservists, the scheme, to be run by outsourcing firm Capita and the MoD, is now two years behind schedule and will cost a further £1m a month until the failure is fixed.

According to a confidential report carried out by Gartner and seen by The Times, the Army’s recruitment wing picked the wrong bidder to build the hosting platform after failing in 2011 to challenge an MoD policy that favoured the less suitable of two competing offers.

So far the hosting platform has cost up to £15.5m and the MoD is considering spending a further £50m to fix the problem.

Gartner also reported that the project management team was under-resourced and when delays started, the Army failed to take charge and implement a viable contingency plan, resulting in spiralling costs.