Gordon Brown, the UK chancellor and likely next prime minister, has exhibited a “Stalinist ruthlessness” in government, belittling his cabinet colleagues whom the Treasury treats with “more or less complete contempt”, according to the man who was Britain’s top civil servant until two years ago.

In an interview with the Financial Times, Lord Turnbull, permanent secretary to the Treasury for four years under Mr Brown before becoming cabinet secretary in 2002, accused the prime minister-in-waiting of a “very cynical view of mankind and his colleagues”.