Just a day after the government rejected advice from the cabinet secretary, Gus O'Donnell, to prepare a "Plan B" for the economy, the worst employment figures since the start of the year are published.

The jobless total increased by 35,000 in the three months to October to 2.5 million (7.9 per cent) and long-term unemployment rose to 839,000, up by 41,000 over the three months and the worst figure since 1997. Turn to youth unemployment and the picture only gets grimmer. The number of 16-to-24-year-olds out of work increased by 28,000 to 943,000, one of the highest figures since records began in 1992 and a jobless rate of 19.8 per cent.

The $64,000 question remains this: will job creation in the private sector be sufficient to offset job losses in the public sector? It would be complacent of George Osborne to assume so. The sector that created a mere 300,000 jobs between 1993 and 1999 is now expected to create more than two million between now and 2015.

There is something dangerously arrogant about a government that rejects all talk of a "Plan B" – merely an exercise in contingency planning – on the grounds that its approach is beyond question. Vince Cable's attack on Treasury officials as "Thirties fiscal fundamentalists" suggests that not everyone in the coalition is so sanguine.

Osborne may have already declared triumphantly: "The plan is working." But he could live to regret such hubris.