The RAF scrambled Typhoon fighter jets on Wednesday from RAF Leuchars in Fife after two long-range Russian Tupolev
Tu-95s – known by Nato as Bears – approached UK airspace.
The strategic bombers – which are also used for high-level surveillance – were shadowed off the north-east of Scotland before flying towards Russia, with Danish planes also monitoring them.
The Typhoons are part of the UK’s quick-reaction force to deal with sudden incursions.
The MoD last night claimed that an independent Scotland would not be in a position to deploy the same response because its proposals would leave it short of aircraft.
The Scottish Government’s white paper says an independent Scotland would have 12 Typhoons.
But, because of maintenance schedules and intensive training, Scotland would only have four available to deploy at any one time.
This compares to 148 Typhoons currently serving with the RAF across the UK.
The SNP acknowledge the Arctic “high north” as a defence priority because of the threats posed by Russia in the region.
But the lack of quick-reaction aircraft would be a gap in that strategy, according to MoD sources.
They noted that Denmark and Norway – which also have concerns about the high north and are similar in size to Scotland – have much larger fast-jet capabilities: Denmark has 45 fast fighter jets and Norway has 57.
An MoD spokeswoman said: “The government is clear that Scotland can only be certain of its security by remaining part of the UK family. With just four jets available to deploy at any one time, from a squadron of 12, an independent Scotland would be less able to provide a quick-reaction alert force in response to unidentified threats on a sustained basis.
“These four aircraft would be required to protect the entirety of Scotland’s skies from the borders of England, to well out over the North Atlantic and the Irish Sea. Without air-to-air refuelling aircraft, a Scottish air force would be forced to leave large parts of Scotland’s airspace undefended.”
But last night a senior Scottish Government source pointed out that the MoD plans to close RAF Leuchars and turn it into an army barracks by 2020, leaving Scotland with just one airbase – RAF Lossiemouth in Moray.
The SNP has already questioned why £100bn needs to be spent on a Trident replacement when Westminster has been cutting conventional forces.
They also highlighted the lack of a maritime surveillance aircraft since the cancellation of the Nimrod replacement in 2010 which has left the UK exposed to Russian incursions, including a naval battlegroup entering Scottish waters in 2011 and last year.
A Scottish Government source told The Scotsman: “This is unbelievable hypocrisy, coming from the Ministry of Defence which has already announced it is to close RAF Leuchars as a front-line airbase.
“And it follows recent episodes where the MoD had to radio Scottish trawlers in the Moray Firth to ask if they knew the whereabouts of a Russian aircraft carrier, as there are no major Royal Navy surface ships based in Scotland – and no maritime patrol aircraft following the scrapping of Nimrod.”