The rouble smashed through resistance to an all-time low of 65.5 to the dollar, falling a jaw-dropping 11%, in a crescendo of selling on Monday, as oil prices continued to slide and markets braced for a likely default in Ukraine.

The Russian currency has lost half its value since President Vladimir Putin first sent forces into Ukraine, setting off a chain of events that the Kremlin can no longer control.

In the bleakest official forecast yet from Moscow, the Russian central bank warned that the country could see a 4.5 per cent to 4.7 per cent contraction in GDP next year if oil prices remained at $60 a barrel.