A political background to the Budget

Philip Hammond began his Budget speech in March by noting that the previous Chancellor to deliver the 'last Spring Budget' was Norman Lamont, who was sacked ten weeks after doing so. 'Wish me luck!' joked Mr Hammond, but in the days and weeks that followed he may have wondered if he had needlessly tempted fate.

He was forced into an immediate U-turn on the Budget's key announcement - a rise in national insurance contributions for some self-employed workers - after backbench Tory MPs complained that it contradicted their manifesto commitments.

Then came Theresa May's snap General Election in June, in which the Conservatives unexpectedly lost their overall majority and were forced into a supply-and-confidence agreement with the Democratic Unionist Party.

More recently, Mr Hammond created unwelcome headlines when he referred in an interview to the EU's Brexit negotiators as 'the enemy' - a remark he subsequently described as 'a poor choice of words'.

So the lead-up to Mr Hammond's first Autumn Budget has been far from easy, and his announcements will be intensely scrutinised. Despite all this, there has been some encouraging economic news for the Chancellor. Unemployment is at a 42-year low and productivity increased by 0.9% in the latest three months - the strongest growth rate for six years. But Mr Hammond was always unlikely to want to tempt fate again by being overconfident. As he said recently to the BBC: 'I always operate on the principle - I think it is a sound and cautious principle - that everyone is sackable.'