Select Committee Chairs Meg Hillier and Dr Julian Lewis have written jointly to the Prime Minister to highlight their increasing concerns about the "severe budgetary pressures" faced by the Ministry of Defence (MoD).
It states: “We are concerned that new commitments and emerging threats means the budget will not deliver all that is promised.
“The existing affordability gap affecting traditional defence equipment and support programmes, combined with the intensification of new threats such as cyber, chemical and biological attacks, risk undermining UK national security as well as our ability to play an effective role in the world.”
While the authors agree that the MoD should make "efficiency savings" when possible, they highlight issues with specific plans:
"We are concerned that the Modernising Defence Programme will not be able to deliver the additional capabilities required to respond to new threats and undertake necessary organisational reforms within the existing budget.
Last month, a report issued by the Public Accounts Committee found that the 10-year Defence Equipment Plan faces an affordability gap of at least £4.9 billion, rising to £20.8 billion if all identified risks materialise.
The letter also focuses on the F-35 jets, expressing 'considerable concern at the uncertainty around the full costs of one of the most important defence investments'.
Hillier, who chairs the Public Accounts Committee, and Dr Lewis, who chairs the defence equivalent, conclude by saying that "such concerns are not simply about balancing the books":
"The very real effects of inadequate funding can be seen in the extremely worrying decline in morale amongst our Armed Forces, shown very starkly in the latest results of the Armed Forces Continuous Attitude Survey".