The SNP has raised fresh concerns about military cutbacks after a patrol vessel was sent to intercept Russian naval vessels in the English Channel.
HMS Severn, a 1,700-tonne ship armed with three machine guns and currently involved in fishery protection, was sent to track the two Russian craft this week.
Angus Robertson, Moray MP and SNP defence spokesman, has previously questioned gaps in the cover provided by the “Fleet Ready Escort” destroyer, which is dedicated to such tasks.
He highlighted the issue after Russia’s largest aircraft carrier, the Admiral Kuznetsov, and its support vessels arrived in the Moray Firth several times in recent years.
Mr Robertson said: “A dedicated ‘Fleet Ready Escort’ frigate or destroyer is supposed to be available at all times to cover circumstances, including unexpected visits close to UK shores by navies from other countries.
“The Ministry of Defence has admitted it has been ‘gapped’ without a ship available twice in recent years.
“This could well be another example of that. I will be asking urgent questions about this in the Commons.”
A Royal Navy spokesman said that the encounter was part of “a well-established and standard response”.