“The government is using the “extremely expensive” Hinkley Point C nuclear power station to cross-subsidise Britain’s nuclear weapon arsenal, according to senior scientists.

In evidence submitted to the influential public accounts committee (PAC), which is currently investigating the nuclear plant deal, scientists from Sussex University state that the costs of the Trident programme could be “unsupportable” without “an effective subsidy from electricity consumers to military nuclear infrastructure”. …

“What our research suggests is that British low-carbon energy strategies are more expensive than they need to be, in order to maintain UK military nuclear infrastructures,” said Stirling.

“And without assuming the continuation of an extremely expensive UK civil nuclear industry, it is likely that the costs of Trident would be significantly greater.”

The Hinkley Point project has been criticised for its huge cost. The French electricity company EDF is currently in the early stages of constructing the plant near Bridgwater, Somerset, in partnership with the China General Nuclear Power Group.

The government has agreed a minimum price of £92.50 per megawatt hour (MWh) for electricity produced by Hinkley Point, the first new-build nuclear power plant in the UK since 1995. Under this agreement, if the usual wholesale price is lower, the consumer pays the difference in price. The current wholesale electricity price is around £42 per MWh, so the electricity consumer would pay EDF an extra £50 per MWh.

Last month, the government agreed a “strike price” of £57.50 per MWh for offshore windfarms off Scotland and Yorkshire, far below the Hinkley guaranteed price.

This week, the Green MP Caroline Lucas asked the government about the Ministry of Defence and the business department discussing the “relevance of UK civil nuclear industry skills and supply chains to the maintaining of UK nuclear submarine and wider nuclear weapons capabilities”.

Harriett Baldwin, the defence procurement minister, answered that “it is fully understood that civil and defence sectors must work together to make sure resource is prioritised appropriately for the protection and prosperity of the United Kingdom”.

Johnstone said the decision-making process behind Hinkley raised questions about transparency and accountability, saying: “In this ever more networked world, both civil and military nuclear technologies are increasingly recognised as obsolete. Yet it seems UK policymaking is quietly trying to further entrench the two – in ways that have been escaping democratic accountability.”