BAE Systems has been warning for several months that it would have to start laying off staff without more work to fill the gap between the ending of building of the two Queen Elizabeth class aircraft carriers in 2016-17 and the ramping up of the Type 26 frigate contract at the end of the decade.
Observers of the Type 26 project have long suspected that the London government had been putting off giving it the formal go-ahead until the outcome of the September 2014 Scottish independence referendum is known.
It had been believed that London would try to keep all its options open ahead of the referendum, allowing the MoD to seamlessly switch the Type 26 project from Scotland to Portsmouth if the referendum had gone the way of the SNP.
However, the financial pressure was so great that the MoD could only find the money to keep the Scotstoun and Govan yards in business.
Although this has made the Royal Navy and BAE Systems happy, because they both think the Scottish yards have the most suitable infra-structure and properly trained workforce to take on the Type 26 project, it leaves the London government in a high stakes game of poker over the fate of the Scottish yards.
An independence vote would result in a major re-jigging of the project and its re-location to an English or Northern Ireland yard. This would involve considerable dislocation and extra cost, most likely involving the costly re-opening of the Portsmouth facilities the MoD has just said it would close.
One of the most depressing things about the debate that followed the BAE Systems announcement yesterday was the posse of politicians lining up to call on people not to “play politics” with shipyard workers jobs. They all seemed to be doing exactly that.
• Tim Ripley is a defence analyst