The Royal Navy has avoided capturing any Russian tankers from the so-called shadow fleet, amid concerns that such actions might violate international law, sources revealed today.

Last month, Sir Keir Starmer announced that British forces would have the authority to intercept and board Russian vessels under international sanctions that venture into UK territorial waters.

However, no Russian tankers have been apprehended in the English Channel so far. This includes two ships that were escorted by a Russian frigate through the area just this Wednesday.

Reportedly, Attorney General Lord Hermer has advised government officials that it would be legally permissible for special forces or National Crime Agency personnel to board these tankers.

Nevertheless, it appears that no operations have been initiated, largely due to concerns about potential violations of international maritime law.

International law imposes stringent criteria for boarding a foreign ship; authorities must present a convincing legal argument for each action, demonstrating that the ship is indeed in violation of British sanctions.

However, a government source rejected the claims, saying: ‘The Attorney General has been working alongside the Defence Secretary to step up action against Russian shadow fleet activity. 

‘They both recently convened representatives from Joint Expeditionary Force ally nations to discuss the legal framework for military action.’

The frigate Admiral Grigorovich was seen accompanying two ‘shadow fleet’ vessels past Britain’s south coast on Wednesday (file pic)

It follows a separate report that one of the sanctioned Russian tankers that sailed through the Channel on Wednesday was carrying supplies for Putin’s military. 

Universal was spotted sailing west along the south coast alongside frigate Admiral Grigorovich and one other ‘shadow fleet’ tanker, with the Royal Navy only able to rustle up one support ship to monitor them.

Last month, Sir Keir gave approval for Britain’s commandos to board and halt shadow fleet vessels as they pass through UK waters in an attempt to ‘go after’ the sanction-breaking ships ‘even harder’.

But RFA Tideforce, an auxiliary tanker armed with only light defensive weapons, followed the three-ship flotilla past Dover without intervening.

Universal’s cargo included oil, supplies and spare parts for the direct use of Russia’s army, a Nato maritime security source told The i Paper. 

The vessel was followed by Enigma, a second sanctioned Russian tanker sailing under a fake Cameroon flag. 

Universal left a port near Saint Petersburg at the end of last month amid a series of Ukrainian drone attacks on ports in the region before picking up its warship escort in the Baltic Sea on April 2.      

The Foreign Office sanctioned the ship in September for its role in exporting sanctioned Russian oil to fund Putin’s war in Ukraine.  

But the Nato source said the ship was carrying a more nefarious cargo including fuel, food, and spare parts for Russian military ships ‘operating at a distance’ from Ukraine.

They believe it was heading west through the Channel to escape Ukrainian military action in the Baltic. Pictures suggested it was not follow loaded, which may mean it was forced to leave prematurely to escape the attacks. 

Moscow’s shadow fleet is reported to be made up of more than a thousand ageing tankers.

A satellite image released by the MoD of a spy sub seen in British waters last month 

They illicitly ship oil and other goods out of Russia by flying the flags of other countries, with the aim of evading sanctions imposed by the West since the invasion of Ukraine began.

Countries Finland, Sweden and Estonia have recently intercepted suspected shadow tankers travelling through the Baltic, but many have traversed the Channel without challenge. 

Sir Keir has been branded ‘all mouth and no trousers’ on defence by Tory leader Kemi Badenoch, who hit out at his failure to adequately rearm Britain. 

But yesterday, Defence Secretary John Healey claimed Russia’s decision to deploy a frigate to accompany the Universal and Enigma tankers indicated the UK’s approach was having an effect. 

Answering questions after a Downing Street press conference which he used to reveal British armed forces had foiled a Russian submarine operation in UK waters, the Defence Secretary said: ‘We’ve got a strong history as a country for sanctioning ships, individuals, and with allies.

‘We’ve seen two things in the last year. We’ve seen over 200 of the Russian sanctioned shadow fleet put out of action and forced to anchor, putting more pressure on Putin’s ability to fund his illegal war in Ukraine, and we’ve seen the oil revenues that Russia takes from the illegal trade drop by a quarter.

‘But there’s more we can do. As the Prime Minister has announced, we are ready. We have the military options, and we’re ready to take action, not just in support of, but actually with allies, to interdict shadow fleet vessels.

‘I would just suggest to you, if the action we’ve already taken, the action that the Prime Minister has indicated we’re ready to take in addition, is making Russia re-route its shadow ships as it has, or escort its shadow ships with its own warships, then the stance, the military posture, the determined work that we’ve done, particularly with JEF (Joint Expeditionary Force) allied nations, is having an impact and making it harder for Putin to pursue his illegal oil revenues, coordinate and run his shadow fleet and fund his illegal war in Ukraine.

‘And we aim with others to put more pressure in the coming weeks and months on that activity.’

The Prime Minister gave approval for the UK to start seizing shadow fleet vessels as he travels to Helsinki, Finland, for a summit with national leaders from the Joint Expeditionary Force (JEF).

Announcing his plan to allow commando raids, Sir Keir said in March:  ‘(Russian President Vladimir) Putin is rubbing his hands at the war in the Middle East because he thinks higher oil prices will let him line his pockets.

‘That’s why we’re going after his shadow fleet even harder, not just keeping Britain safe but starving Putin’s war machine of the dirty profits that fund his barbaric campaign in Ukraine.

‘He and his cronies should be in no doubt, we will always defend our sovereignty and stand with Ukraine for as long as it takes.’

British forces have already been involved in tracking shadow fleet vessels for several years, and have supported operations by other countries to seize the ships.

Speaking at the London Defence Conference this morning, Mr Healey admitted he would like more money from the Treasury. 

‘Would I like more resources? Yes, I would. Every Defence Secretary would. Those [resources] will increase.

‘Yesterday was an important reminder that while all eyes are on the conflict in the Middle East, the primary threat is rising Russian activity.

‘Yesterday we exposed a failed covert Russian operation. We know Russia operates with deniability, we have seen in the Baltics cables cut by suspect vessels. Yesterday we said to Putin we see you, we are exposing you and if there is any damage then you have not got that deniability.’