Ministers have been pressed to reveal more about the hunt for a foreign submarine off the west coast of Scotland.

Angus Robertson, Scottish National Party group leader in Westminster, made the call in the Commons, amid reports that Nato spy planes have been called in to help find the vessel.

Raising a point of order, Mr Robertson, who also speaks for the SNP on defence issues, told Commons Speaker John Bercow: "In the last day news has emerged of a large-scale maritime security operation taking place off the Scottish coast.

"It is doing so in circumstances where the UK MoD is unable to deploy any maritime patrol aircraft and has had to depend on MTA provided by the US, Canada and France.

"Given how serious a situation this is, have you been advised by the MoD that they intend to make a statement to the House so that we as parliamentarians can be informed of this situation?"

Mr Bercow replied: "I have not been so advised. I have no indication a minister intends to make a statement.

"But you have made your point with force and alacrity and knowing you as I do I rather feel that if you consider you have got a good point, you are not likely to let go of it and it is conceivable even that at appropriate points he might repeat it."

At the height of the operation, five aircraft from four different nations with Royal Navy warships were involved in the search for the mystery vessel, according to a report by Aviation Week.

The MoD said yesterday it had received assistance from Nato allies but would not say whether they had been searching for a submarine.

The hunt was said have been launched after a periscope was spotted in waters where Royal Navy submarines normally surface as they head into or out of their base at Faslane late last month.

Since the Government scrapped its Nimrods in the 2010 Strategic Defence and Security Review, the UK has lacked a specialist maritime patrol aircraft.