In an area where the heavy industry of coalmining and steelmaking has ceased, he said, “new industry and employment opportunities are so important to creating hope and growth in our communities”.

Jones asked a government minister how long the investigations were expected to take, saying “the longer this uncertainty goes on this will have an impact on the morale of the workforce”.

Labour’s Newport West and Islwyn MP Ruth Jones said many of her constituents were employed by General Dynamics and called for the facts to be “identified urgently”.

“Any delay in the conclusion of these investigations comes at a cost,” she said.

“It means workers concerned about their future, ongoing confusion about the safety of the rigorously tested Ajax, and opportunities to export Ajax to our allies being put at risk.”

She said the Ajax programme was “an extremely welcome product of a deliberate choice by successive governments”, and that the General Dynamics facilities were “a critical part of the Welsh manufacturing landscape”.

Nia Griffith, Labour MP for Llanelli, said ministers needed to fully analyse the latest test results on noise and vibration limits as soon as possible and make decisions on next steps “without delay”.

“Time is of the essence,” she said.

She added it would be unforgiveable if the latest tests “vindicated the quality and viability of the Ajax project” only for it to be delayed “within ministerial schedules and the machinery of government”.