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?'Heavily-armed personnel were seen taking control and checking through paperwork on the bridge Keir Starmer insisted the six-hour operation – carried out in 'close coordination' with the French – was 'successful' and 'reminds Russia' that the UK is prepared to act