Until now, warships have sometimes patrolled alongside Russian-flagged commercial ships.

But Steregushchy-class corvette Boykiy was recorded escorting dubious foreign-flagged sanctioned vessels passing the English Channel.

The move appears to be a clear challenge to Britain.

It escorted the tanker Selva, a Panama-flagged vessel which is sanctioned by Britain, according to maritime specialist Mark Douglas and OSINT expert Christian Panton.

The ship – part of a Russian-sponsored fleet seeking to evade sanctions over the Ukraine war – has since switched to the flag of Palau.

The 343ft long Boykiy also escorted the Sierra tanker – aka Suvorovsky Prospekt – listed as flagged to Malawi, and sanctioned by the UK and EU.

The move in recent days appears a deliberate provocation by Russia to test Britain and EU resolve to stop tankers used by the ‘shadow fleet’, seen as a means of busting sanctions.

The vessels are now in the North Sea, heading north.

The English Channel deployment mirrors what Finland’s defence minister Antti Häkkänen noted in the Baltic.

“What is new is that Russia is now protecting tankers belonging to its shadow fleet in the narrow waters of the Gulf of Finland,” he said.

“This involves military escort operations and the presence of armed forces. That is a completely new development.”

Russia is also building up a massive military concentration near Finland’s eastern border.