The Russian rouble has suffered its steepest one-day drop since the default crisis in 1998 as capital flight accelerates, raising the risk of emergency exchange controls and tightening the noose on Russian companies and bodies with more than $680bn (£432bn) of external debt. The currency has been in freefall since Saudi Arabia and the Gulf states vetoed calls by weaker Opec members for a cut in crude oil output, a move viewed by the Kremlin as a strategic attack on Russia. A fresh plunge in Brent prices to a five-year low of $67.50 a barrel on Monday caused the dam to break, triggering a 9pc slide in the rouble in a ... (full story)