SUPERMARKET security staff on the look-out for shoplifters could find themselves guarding Britain’s nuclear deterrent at Faslane and Coulport the next day, according to the country’s biggest trade union.

Unite said it was concerned that proposals to privatise the Ministry of Defence Guard Service (MGS) will lead to a drop in standards and training, with the potential for adverse repercussions for the security of bases such as those in Scotland.

More than 2000 guard are employed by the MGS providing unarmed security at more than 100 MoD sites – including its main building in Whitehall, London, and naval bases at in Portsmouth and Devonport.

Some aspects of the guarding project are known to be currently under review, with work ongoing to identify improved value for money options.

Safety and security at all MoD sites are given a high priority, especially in times when the threat of terrorism is high, but the organisation does not normally comment on site-specific arrangements.

Mike McCartney, Unite’s national officer for the MoD and government departments, said: “The UK Government is planning to open up the MGS, whose personnel are well-trained, to privatisation.

“Unite wholeheartedly opposes these plans and considers any such proposals are irrational and dangerous to the security, not only of MoD sites but to the security of our service personnel, their families and to all the civilians employed across these sites.

“If these proposals went ahead we could see someone deterring shoplifters at a supermarket on a Sunday then that same person turning up to guard a nuclear site on Monday.

“Employment conditions, training and standards could be compromised in ‘a race to the bottom’ by a private company keen to maximise profit.

“The prospect of an outsourcing company such as G4S, which was in charge during December’s prison riot in Birmingham and responsible for the security fiasco at the 2012 Olympics, taking over the MGS makes the heart sink and should be a matter of serious public concern.

“The MoD believes that by privatising the MGS there could be a saving about £17 million over five years, however, Unite does not believe that these savings could be made.

“We further believe that this is not a cost saving exercise, but merely a ruse so the MoD can meet the Government’s target to axe 30 per cent of the civilian workforce across the whole of the MoD.”

He added: “These controversial plans should be dropped immediately.”

Unite said private security companies would be required to bid on criteria which currently considers them on a ratio of 70 per cent on price and 30 per cent on quality.

The union has met with Nia Griffiths, the shadow defence secretary, who has now tabled a question to Defence Secretary Sir Michael Fallon.

It has also made contact with Labour MSP Jackie Baillie, whose Dumbarton constituency includes Faslane.

She has also written to Fallon and tabled a motion at the Scottish Parliament calling for a debate.

A spokesperson for the MoD said: “We are reviewing the way we provide our guarding at some sites but would never make changes that put safety and security in jeopardy.

“No final decisions have been made and senior staff of the MoD Guard Service, trade unions and security representatives will be engaged in this process.”