Many members would have arrived home from work on the day to find out from local media that their jobs were likely to be lost. Negotiator John Ferrett said the union did not receive advance notice of the announcement. “News management seems to have come above the needs of employees undertaking vital work at the base.”

Ferrett said a period of emergency discussions would now take place with the company. The union will demand that BAE give a jobs guarantee to staff affected – that any employee who wanted to stay with the business should have the opportunity to do so.

Ferrett said the fear among members was that BAE would pursue a rapid run-down of shipbuilding, which will see highly-skilled staff leaving the business early.

“We had expected that any run-down on the shipbuilding side would have been synchronised with the upcoming service and maintenance requirements for the new aircraft carriers. As it stands, the company faces huge costs in closing the facility as well as similar costs in recruitment and training of new workers to support the carriers.”

Prospect has warned that a complex operation like a (military) shipbuilding yard cannot simply be turned off and then back on again at a later date.

Ferrett said staff had worked hard to make shipbuilding work at the base since BAE took its operation over, making sacrifices to maintain its competitive edge, only now to be thrown on the scrapheap.

The decision would leave the UK without any sovereign shipbuilding capability should Scotland vote for independence in 2014.