Key questions

• Why is the Budget so important?

Apart from being the major set-piece event where the chancellor sets out how the government will spend the nation’s money, this Budget arrives at a time of acute political sensitivity.

Since losing the Tories’ parliamentary majority, and some of her authority, at the general election, Theresa May has suffered a series of setbacks including Cabinet resignations and a botched coup attempt.

There is also a lot on the line for Mr Hammond, who will have Brexiteers who want him sacked over his perceived support for a “soft” Brexit.

• What are the immediate pressures on the chancellor?

Many Tory MPs are said to want a change in direction after Labour’s unexpected gains in the election on an anti-austerity ticket and with an apparent surge in youth support.

Mr Hammond is facing calls to give public sector workers a pay rise but could face a backlash.

• Will Mr Hammond and Mrs May come out unscathed?

Budgets can unravel as the detail is unpicked in the days after the set-piece speech, which is often precision-engineered to deliver positive headlines.

The stakes are too high for Mr Hammond to make any mistakes this time.

That in turn could further weaken Mrs May going into a crucial phase of Brexit negotiations.