Laura Kuenssberg

partly because in some cases there were other Russian vessels protecting tankers.

Secondly, because there were concerns about making sure they had sort of the right legal justification, but also they needed to ensure the right cargo was on the ship.

to prove it is part of a shadow fleet.

And with those sort of different boxes ticked, it meant that tonight was the night that those Marine commandos and all of these quite long list of aircraft got involved and apprehended the SMERTOS, previously the MERTOS.

Right.

Well, it's now on its way to an anchorage in the southeast of England.

It represents a more muscular approach by the UK government because other countries have boarded these tankers from the Russian oil fleet.

the shadow fleet, which is said to carry 75% of sanctioned oil.

So we had BBC's Frank Gardner on Radio 4 today, and I asked him if he was braced for this, if he was anticipating this.

And certainly it seems to be very intense in terms of the capabilities that we use just for this single ship.

In terms of the list of stuff that the MOD have given us, they talked about aircraft from the Maritime Air Group, Chinooks, Merlin MK4 and Wildcats.

There was also this P-8 aircraft, which is a sort of big surveillance aircraft, normally used to be chasing submarines rather than Shadow Fleet ships.

And then the HMS Sutherland, a frigate, which is again a submarine hunter, but also the HMS Ledbury, which is a mine hunter.

And that's, of course, in addition to those Marines you mentioned, guys, but also the Specially Trained Officers for the National Crime Agency.

If there are around 500 that are sanctioned out of what we think is maybe 700 plus total ships in the Shadow Fleet.

I mean, there are a lot of opportunities perhaps in the coming months to try and intercept them.

But that in itself will be very labour intensive and pretty expensive too, maybe.

Well, Frank said this is an expensive operation.

And therefore, it does lead in to the question of the wider arguments been had in the past few days, including resignations.

the defence investment plan and basically put how much money have we got to do things including this.