The Ministry of Defence (MOD) has "neglected" the state of housing for troops over many years, taking for granted the "goodwill" of service personnel, MPs have said.
The cross-party Public Accounts Committee said in a report published on Friday that declining satisfaction levels with military accommodation cause a risk of troops leaving service early.
A "fix on fail" policy was said by MPs to have led to a £1.5bn backlog on maintenance and repairs across all housing.
Satisfaction has dropped among those in single living accommodation from 58% in 2015 to 49% last year, with some experiencing issues with "basic amenities", including hot water.
The report concluded: "Ultimately, a failure to look after Armed Forces personnel properly affects the ability of the services to deliver operational capability, yet the department has taken the goodwill of service personnel for granted and has been complacent in how it has managed its single living accommodation."
The MPs found the MOD has "neglected single living accommodation for many years".
The report also raised concerns that the extra £16.5bn in defence funding announced in November seemed to have been "spent more than once, before it even arrived in the department", despite expectations it would help address housing concerns.
Meg Hillier, the Labour MP who chairs the committee, said: "Providing decent accommodation is part of a promise the MOD makes to our Armed Forces in recognition of their service, a promise which is being roundly broken.
"More airy promises to allot some of the new £16.5bn defence funding, that seems to have been spent several times over before it's even arrived with the department, absolutely will not do – our serving personnel's needs must not be relegated to the back of the queue yet again.
"They deserve better than this and full, proper delivery of the UK's defence capabilities demands it," she added.
Conservative MP for North West Durham, Richard Holden, who is also on the committee, said housing "clearly has a significant effect" on retention in the military.
He told Forces News: "When you're thinking of the amount of money it costs to recruit and train a soldier, if they're then in accommodation which is so substandard that it's a real reason that they're leaving, then we've got real issues and it's actually got knock-on effects for the rest of the MOD budget as well."
WATCH: Richard Holden speaks to Forces News.
Mr Holden added "it's not a new problem at all" and said there is an "element of complacency", continuing that "particularly on the worst aspect of single living accommodation, they really need to get a grip on it".
He continued: "As the Public Accounts Committee, our job is to ensure public money is properly spent on things that people want and, for our soldiers and personnel, that has got to be reasonable accommodation."
An MOD spokesperson said: "Our Armed Forces personnel are at the heart of everything we do and it is only right they are provided good quality and affordable living accommodation.
"We have secured a substantial settlement of more than £24bn over four years that will underpin the modernisation of the Armed Forces, including the defence estate."
Cover image: Single living accommodation block on Salisbury Plain, Wiltshire.