The GMB union has warned new Defence Secretary Grant Shapps that the UK’s efforts in Ukraine risk being undermined if a Ministry of Defence dispute in Beith is allowed to spread.

More than 50 workers, who handle and load missiles at the site, run by the MoD’s equipment agency DES, have been on strike for several weeks in a dispute over bonus payments given to some workers and not others.

The site assembles a variety of weapons, including Storm Shadow and Brimstone missiles, both of which are being supplied to Ukraine’s frontline forces.

Meanwhile another pay grievance has been submitted at another MoD site - not identified by the GMB - with members being balloted on a pay offer.

Mr Shapps, who was appointed on Thursday after the resigniation of previous defence secretary Ben Wallace, used his first public statement to pledge continued support for Ukraine.

But the GMB says this support is at risk due to an ongoing dispute among Mod workers who assemble, store and transport munitions vital to the war effort.

Ukrainian trade unions and politicians have themselves supported the striking workers.

Kevin Brandstatter, GMB's national officer, said: “GMB members at the Ministry of Defence play an absolutely vital role in supporting the UK’s efforts in Ukraine. 

"Many of the missiles they work on go directly to the Ukrainian frontline.

“But a failure to settle this dispute by the employer and the Ministry of Defence means that effort is being undermined.

“These workers are fundamental to the effective operation of these important defence sites. All they are asking for is the fairness they deserve.

“We urge the new Defence Secretary to meet these workers and work to resolve this dispute, so that the important work being done to support Ukraine can continue.”

A spokesperson for the Ministry of Defence have insisted: “The strikes will have no effect on our ability to provide capability to Ukraine.

“Pre-planned contingency measures are being implemented at DM Beith to ensure the continued operation of the site.

"We remain open to dialogue with GMB to discuss the issues raised and work towards resolving them.”