Kremlin-controlled media has mocked Britain as being "naked under the waves" after reports that all of the Royal Navy's strike subs are out of order.

Newspapers, news agencies and TV stations close to President Vladimir Putin were quick to gloat about problems plaguing the UK's multi-billion-pound fleet of seven underwater 'hunter-killers'.

In a PR nightmare for the cash-strapped MoD, Russian-language editions of Sputnik, the Kremlin's main propaganda and disinformation vehicle, described Britain's undersea home defences as being "naked".

British military authorities have denied the reports, which serious Russian commentators have dismissed as an effort by admirals to get more money from the MoD for the fleet.

A Royal Navy Astute class hunter-killer submarine

However, Kremlin sneering comes amid a series of embarrassments for the Royal Navy highlighted by Russian media, including the failed test launch of a Trident missile and much-repeated revelations from a senior commander that Glasgow-made Type 45 destroyers clatters so much like a "box of spanners" that Russian subs can hear them coming.

Pro-Kremlin Life News suggested the defence assets were broken and there was no money to fix them. "The waves", it concluded, "now rule Britannia".

Russia's own navy – often seen as the Cinderella branch of the country's military – has had its own technical glitches, including the Kursk nuclear submarine disaster, in recent decades. These were not cited in any of the stories.

Britain's military and strategic place has come into question ever since Brexit, which was positively reported by Kremlin propaganda channels amid concerns Putin wished to weaken the Western Alliance. A Nato spokesman on Friday dismissed Sputnik, which has an Edinburgh base, as a forum for dispensing disinformation and conspiracy theories.

This prompted John MacDonald of the Scottish Global Forum, a think tank, to stress that news of hunter-killers being out of action would send out a signal of weakness to Britain's friends and potential foes.

He said: "This could not come at a worse time as Russian sub activity out of the Arctic and down to UK waters, notably around Faslane, is at Cold War levels. Operationally, this is bad. In PR terms, it may also send out a message of unpreparedness to UK allies and to Russia. Symbolism (specifically, demonstrating strength) is all-important in Russia-NATO relations."

Mr MacDonald said the revelations also added strength to opponents of nuclear weapons. "There is a glaring lack of money to do what is required to maintain the functioning Navy the UK thinks it needs," he said. "Financial pressures are pressing. This nourishes Trident opponents: we cannot afford to pay for nuclear and non-nuclear forces from the same MoD budget."

Not all Russian coverage was mocking. Some was highly sceptical about the scale of Britain's submarine problem. The Zvezda TV station – which is owned by the the country's Ministry of Defence, cited defence expert Viktor Baranets dismissing stories as spin.

"Generals in England are just as cunning as those in the rest of the world," he said. "In order to squeeze more money for their nuclear subs they have to whine and bellyache and show their fleet isn't in a presentable condition." The Russians, he said, knew subs had been highly active.

Britain's entire submarine fleet will be based at Faslane from 2020. The UK has four Trident carriers, all currently based at the Scottish base, plus seven hunter-killers, three of them new £1.2bn Astute class boats and four older Trafalgar-class vessels.

The Sun reported that the seven hunter-killers were not operational, because they were either undergoing repairs or on trials. This, the report said, was the first time this had happened in decades. Brendan O'Hare, the SNP MP whose constituency includes Faslane, described this as "chilling". The Trident boats are operational. Military sources, however, told The Herald the story was "categorically untrue".

An official 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."