Mikhail Margelov, in an interview with the Russian Izvestia daily, said: “The Libyan premier told me: if the rebels seize the city, we will cover it with missiles and blow it up.”

Mr Margelov met Libyan Prime Minister Baghdadi al-Mahmudi last month.

“I imagine that the Gaddafi regime does have such a suicidal plan,” he added, saying that Gaddafi still had plentiful supplies of missiles and ammunition.

But Mr Margelov, who has had rare access to senior Libyan officials, questioned reports that Gaddafi could be running out of arms in the drawn-out conflict.