Vladimir Putin is not a man who pulls his punches in public. By all accounts the Russian president is a cautious bureaucrat in private, carefully weighing up all the options before reaching any decision. But in front of a domestic audience he often slips into harsh language, even street slang, to get across his message.

Thus it was two weeks ago, when he received a delegation of leaders from Nashi, the pro-Kremlin nationalist youth movement, at his dacha at Zavidovo outside Moscow. Speaking of the diplomatic confrontation between Britain and Russia over Moscow’s refusal to extradite the suspected murderer of Alexander Litvinenko, the former Russian agent poisoned with radioactive polonium in London, Mr Putin suddenly switched from calm analysis to harsh words.