A Russian shadow fleet tanker was anchored off the Dorset coast last night after it was seized in the first British-led operation against a Kremlin vessel.

Royal Marine Commandos and specialist officers from the National Crime Agency boarded the vessel in the early hours of Sunday in a daring, six-hour raid.

The mission, ordered by Sir Keir Starmer, was praised by Ukrainian President Volodymyr Zelensky as 'an important step against Russia's oil fleet'.

But its timing – the week of the Makerfield by-election and days after the resignations of defence secretary John Healey and armed forces minister Al Carns – raised eyebrows.

Scores of Vladimir Putin's rusting fleet have been allowed to sail unimpeded through the English Channel since Sir Keir threatened interceptions in March.

The dramatic escalation, which was filmed for media distribution, also comes the same week the under-fire Prime Minister jets off to the G7 summit, with military commanders in despair over Labour's failure to publish the Defence Investment Plan (DIP).

Conservative MP and former Army officer Ben Obese-Jecty said the raid against the Cameroon-flagged Smyrtos was 'convenient'. He said: 'Starmer desperately needs to look strong on defence after the Healey and Carns resignations'.

He added: 'It's almost as if Keir Starmer needed to discuss a win around defence before the G7, NATO and a crucial by-election. Hugely positive we've taken this action. The underlying question is why now?'

The Smyrtos had been at sea for nine days after leaving the port of Ust Luga near St Petersburg on June 5 laden with crude.

And early yesterday morning an RAF Poseidon P-8 was cleared for take-off from RAF Lossiemouth, in Scotland, towards the Channel.

Already on station were the Royal Navy's HMS Sutherland and HMS Ledbury acting as a 'surface screen' around the 801ft-long tanker.

Chinook, Wildcat and Merlin helicopters carrying Special Boat Service (SBS) and 42 Commando troops took off from an undisclosed location in the South West where final rehearsals for the raid had taken place.

The Daily Mail understands the SBS, equipped with Canadian C8 assault rifles and night vision goggles were the first to approach the Smyrtos, their Chinook hovering in the darkness over the tanker's 138ft-wide hull.

After fast-roping on to the ship, their role was to secure it. Moving tactically and with their rifles pulled tight into their shoulders, the troops raced to the bridge to neutralise any threat posed by her captain and crew.

They were followed by Royal Marines from 42 Commando whose responsibilities included searching the ship and protecting the National Crime Agency (NCA) officers who do not carry weapons.

Commandos captured 25 crew members on board the vessel. Royal Marines commanding officer Lieutenant Colonel Tom Quinn said crew on the ship did not pose any resistance to the take over, The Sun reported.

Ministry of Defence footage showed Commandos moving in formation down staircases and from room to room and guarding NCA officers as they studied documentation aboard.

After the raid, Sir Keir immediately went on social media to praise the operation while the MoD flooded social media with footage.

Meanwhile the Smyrtos was steered towards Portland where she is expected to remain pending investigations. The tanker has been subject to UK sanctions since 2025.

The intervention seemingly convinced three other shadow fleet vessels to abandon their passage through the Channel.

On TikTok the Prime Minister said: 'This operation delivers yet another blow to Russia and reminds those fuelling Putin's war in Ukraine that they cannot hide.

'I want to pay tribute to all those involved, including our Armed Forces and law enforcement officers who keep this country safe.' The six-hour operation, which government sources insisted had been planned weeks in advance, involved combat helicopters, intelligence gathering aircraft and warships.

Putin uses so-called shadow fleet tankers to evade sanctions on Russian energy products and generate revenue for his illegal occupation of Ukraine and threats to the UK and Europe.

His armada of 700 poorly maintained vessels sail under different flags. These tankers transport an estimated 75 per cent of Russia's sanctioned crude oil, bypassing sanctions and maritime regulations and generating billions for Putin's war coffers. Due to their disrepair the ships also pose a major environmental threat.

In recent weeks the UK has played a supportive role in similar French-led operations but yesterday's raid represents the UK's first clamp down on the Kremlin's illegal trade. Downing Street undertook the legal groundwork for the mission in the wake of a US operation in the North Sea in January.

That month a furious US President Donald Trump was required to send his commandos to the North Atlantic to intercept the Marinera south of Iceland as UK forces were denied the necessary legal protection to take part.

In March, Downing Street announced that UK forces would be able to board shadow fleet vessels transiting UK waters. That announcement also appeared expedient as it coincided with the PM's appearance at a summit of military allies in Finland.

Despite the announcement, a further 200 sanctioned tankers sailed unchallenged through the UK's exclusive economic zone.

The UK has sanctioned more than 500 vessels, prohibiting those vessels entering UK ports or sailing through UK waters. Appearing on the BBC's Sunday with Laura Kuenssberg, Mr Carns predicted more operations would take place in the months ahead.

Conservative leader Kemi Badenoch paid tribute to the 'brave' personnel involved and said her party supported the Government in 'standing with Ukraine'.

Newly-appointed Defence Secretary Dan Jarvis praised the professionalism of those involved in the operation.

Yesterday, he said he was determined to secure the funding required, urging the Government to 'meet the moment'.

Any move by Sir Keir to increase the offer to the MoD in the wake of Mr Healey and Mr Carns' resignations would represent the largest U-turn of his premiership.

Mr Jarvis said: 'The defence of our nation is a shared endeavour. I have a big responsibility in that regard and to those people who expose themselves to risk tonight, tomorrow and next week. We owe them a debt of gratitude.

'I have to make sure they get what they need. People should be very clear about my determination to fulfil those duties.