It found that mistakes in awarding a contract for the clean up of the Magnox sites had cost the taxpayer £122m.

Prospect is the leading union for professionals in the nuclear sector. It is calling for government to both provide the nuclear sector with the resources it needs and also to make a clear public commitment to the future of nuclear in the UK.

Mike Clancy, Prospect general secretary said: “The NAO report raises serious questions about the ability of government and the Nuclear Decommissioning Authority to manage such large and complex projects.

“With pressure across the public sector to contract out services it also raises questions around the ability of government to handle these cases, especially after seven years of cutting staff and funding.

“The NDA cannot be held solely responsible, for its inability to attract key procurement expertise. Government cuts on recruitment and continued limits on pay increases have also taken a heavy toll.

“With the threat of Brexit and risks of leaving Euratom hanging over the British nuclear industry, the last thing it need is more uncertainty. Our members will want reassurance from Ministers that they are committed to nuclear and protecting the expertise and jobs we have in the UK.”