MPs have accused the Ministry of Defence of a "lamentable" failure to properly fund new military equipment required for the armed forces.
The Public Accounts Committee said it was "extremely frustrated" that the MoD had still not made the hard choices needed to plug a £13bn funding gap.
The warning comes ahead of a government review which is expected to overhaul defence procurement.
The MoD said it was committed to securing the best equipment.
In a highly critical report, the Public Accounts Committee - which examines public spending - expressed "extreme" frustration that "we see the same problems year after year".
The MPs accused the MoD of failing to make the "hard choices" necessary to plug a gap of up to £13bn pounds in the current equipment programme.
"The government has still not taken the strategic decisions required to establish an affordable equipment plan and deliver the crucial military capabilities needed by our armed forces.
"The department's lamentable failure to get a grip on the equipment plan continues, despite this committee and the NAO [National Audit Office] consistently highlighting serious affordability issues in the plan year after year."
Committee chair Meg Hillier said: "The MoD knows what it's getting wrong. We know what it's getting wrong.
"For years, we have made concrete proposals to improve delivery of key strategic priorities and here we are again, with the same gaps in our national defence and the same risk to our armed forces personnel, year after year."
Conservative MP Mark Francois recently warned General Sir Nick Carter, chief of the defence staff, that he should "nip back to the department and ask them to sort their bloody selves out, because if not, Cummings is going to come down there and sort you out his own way, and you won't like it."
The prime minister's chief advisor, Dominic Cummings has been a harsh critic of defence procurement in the past.
The government has said its new integrated defence and security review - due to be completed next year - would seek "innovative ways" to promote UK interests while committing to spending targets.
A Ministry of Defence spokesman said: "As the committee acknowledges, managing complex defence programmes can be challenging and we continue to reduce the gap between our budget and predicted costs, achieving £7.8 billion of efficiency savings last year and securing an extra £2.2 billion for defence."