NAVY chiefs are so scared of Theresa May that they haven’t told her that the entire UK fleet of attack submarines are out of operation, according to reports yesterday.

Military sources told The Sun that the UK’s four Trafalgar​-class boats and three Astute-class are undergoing repairs and maintenance.

According to the report, the Navy’s three new Astute-class subs are beset by problems, and the four remaining Trafalgars are said to be “on their last legs”.

If true it would be the first time in decades the Royal Navy has had no attack submarines ready. The Admiralty has not told Downing Street, reportedly, because they fear the Prime Minister’s reaction.

The SNP called it a scandal.

Five have broken down, a sixth, HMS Ambush, is being repaired after crashing into a tanker near Gibraltar last year.

The seventh, HMS Astute, is at sea, but on trials following maintenance, and is not yet ready for mission.

The Vanguard nuclear deterrent subs remain operational.

The problem-hit Astute class are slowly replacing the Trafalgars. The £4bn project has seen construction delayed by more than four-and-a-half years and costs have soared. They have a reputation for breaking down in hot weather.

A Royal Navy spokesman said: “We don’t comment on specific submarine operations. Britain has a world-class fleet, the Royal Navy continues to meet all of its operational tasking, deploying globally on operations and protecting our national interests as Britain steps up around the world.”

In January, Downing Street was accused of covering up a failed Trident missile test involving one of the UK’s Vanguard submarines. The missile was said to have veered off course and the Government refused to answer questions about it, before details were leaked to CNN in the US. Prime Minister Theresa May dodged the question four times in a row on the Andrew Marr Show.

Brendan O’Hara, the SNP’s Defence spokesperson called the report “chilling”.

“Reports of all seven attack submarines being out of action are astonishing. If – as reported – our complete lack of any submarine attack capability was ‘kept from the Prime Minister’ – then it is indefensible.

“First there was the recent Trident malfunction fiasco, now we have this chilling situation. How can we trust those in charge of our defence when we hear about this incompetence and yet another Whitehall nuclear cover up. It is a scandal.”

However, late yesterday afternoon an MoD source said the reports were “categorically not true,”.

“There are operational, capable and attack-ready submarines. Where they might be is sensitive operational information,” the source said.