The Ministry of Defence should fix or scrap its troubled Ajax armoured vehicle programme this year or risk compromising national security, an influential parliamentary committee has said.

The Ajax programme, intended to provide a state-of-the-art reconnaissance vehicle for the army, has already been running for 12 years and cost £3.2bn but has so far failed to deliver a single deployable vehicle.

Originally intended to enter service in 2017, Ajax has been repeatedly delayed due to what the House of Commons public accounts committee (PAC) has described as “a litany of failures” including noise and vibration problems that injured soldiers testing the vehicles.

In a report published on Friday, the PAC said the MoD still did not know when Ajax would enter service or whether the noise and vibration issues could even be fixed two years after they were first raised.

The PAC said management of the programme had been “flawed from the outset” and the MoD had “once again made fundamental mistakes” in planning and managing a major equipment programme. As a result, the committee warned that the MoD was “failing to deliver” the vehicles the army needed “to better protect the nation and meet Nato commitments”.

The PAC chair, Dame Meg Hillier, said: “Enough is enough – the MoD must fix or fail this programme, before more risk to our national security and more billions of taxpayers’ money wasted. These repeated failures are putting strain on older capabilities which are overdue for replacement and are directly threatening the safety of our servicepeople and their ability to protect the nation and meet Nato commitments.”

The MoD said any delays would not come at extra cost to the taxpayer due to the nature of the contract, adding that no further payments would be made to the manufacturer, General Dynamics, until the department was “satisfied with the future trajectory of the programme”.

The PAC report said delays to the Ajax programme had forced the army to make “operational compromises” including prolonging use of the Warrior armoured vehicle, which entered service in 1987.

Although the army is “cautiously optimistic” that Ajax can enter service by 2030, the PAC warned that any further delays would increase the risk of missing even this target and urged the MoD to explore alternatives should the contract with General Dynamics collapse.

The MoD agreed a fixed-price contract with General Dynamics worth £5.5bn for 589 Ajax armoured vehicles, but so far just 26 have been delivered and these can only be used for training purposes.

The PAC said it doubted the programme could be delivered within existing arrangements. The committee said it expected a decision on whether to persevere with Ajax or scrap the programme entirely by the end of the year.

An MoD spokesperson said: “The UK contributes more than its force requirements and readiness levels asked of it by Nato. The defence secretary has been clear that Ajax is a troubled programme. We agree with many of the committee’s recommendations and are actively taking steps to correct these.

“Our firm price contract means any delays will not cost the taxpayer more. General Dynamics have received no payments under the contract in 2021 and 2022. No further payments will be made until we are satisfied with the future trajectory of the programme.”

General Dynamics has been approached for comment.