The British Army has failed to meet recruitment targets as it "under-estimated the complexity of what it was trying to achieve" when it embarked on a project with outsourcing giant Capita, a report has said.
Capita was controversially awarded the £495 million contract for Army recruitment in 2012, but the Army has not recruited the number of soldiers it requires in any year since the contract began.
The Commons Defence Committee was told in October that the Army currently has 77,000 fully trained troops compared with a target of 82,500.
A report by the National Audit Office (NAO), published on Friday, found there were "significant problems" with the British Army Recruiting Partnering Project.
These included an online recruitment system that was planned for launch in July 2013 but launched 52 months late in November 2017 at a cost of £113 million, triple the original budget.
The NAO found the initial delay was caused by the Ministry of Defence, which failed to meet its contractual obligations to provide the IT infrastructure to host Capita's recruitment software.
The Army passed responsibility for developing the whole system to Capita in 2014, but "due to the complexity of the Army's requirements, system development was delayed even further".
Capita has consistently missed the Army's recruitment targets, with the total shortfall ranging from 21% to 45% of the Army's requirement, the report said.
The Army and Capita have introduced some "significant changes" in the last year, but none have resulted in enough soldiers being recruited, according to the NAO.
The report found that it took up to 321 days for new recruits to go from starting an application to beginning basic training, and that many drop out of the process while waiting.
Figures relate to half of regular soldier applicants in the first six months of 2018-19.
A total of 47% of applicants dropped out of the process voluntarily in 2017-18, and both the Army and Capita believe the length of the process is a significant factor in this, the report said.
People trying to join the Army experienced technical problems with the online recruitment system after its launch.
The Army estimates there were 13,000 fewer applications between November 2017 and March 2018 than in the same period the previous year, the report said.
This could lead to up to 1,300 fewer enlistments.
The NAO found that neither the Army nor Capita tested changes to the recruitment process before it was introduced and the number of local recruitment centres was cut from 131 to 68 to save costs.
It said the project will not achieve its planned savings of £267 million for the Ministry of Defence.
Capita's 10-year contract will end in 2022.
Both the Army and Capita "believe that recent changes will improve the recruitment of regulars and officers", the report said.
A Capita spokesman said: "As the NAO report states, both Capita and the Army under-estimated the complexity of this project.
"Our focus is now on working with the Army to deliver a recruitment process fit for the 21st century.
"We have overhauled governance on the contract and are already seeing improvements, with applications at a five-year high and a reduction in the amount of time it takes candidates to join the Army.
"We are absolutely committed to getting this partnership right."
An Army spokesman said: "We are fully committed to improving our recruiting process.
"Working with Capita we have put in place a plan to address the challenges.
"The Army has developed a range of measures to speed up the recruitment process.
"This includes new measures to reduce the time between applying and starting training, greater access to military role models for recruits and a new IT system.
"The Army meets all of its operational commitments to keep Britain safe."
Nia Griffith MP, Labour's shadow defence secretary, said: "This disastrous contract is letting down taxpayers and soldiers alike.
"The Conservatives' ideological obsession with outsourcing has driven up costs and resulted in the failure to recruit enough personnel to the Army."