Since the 2016 vote to leave the European Union, Brexit has become the policy area that dominates debate in the UK. It defined Theresa May’s government and will undoubtedly consume much of the government’s time and energy over the next few years, regardless of how the Brexit agenda evolves or who is in power.

The 2019 Spending Round, published in September 2019, set departmental budgets for the 2020−21 financial year. Chancellor Sajid Javid topped up the spending plans pencilled in by his predecessor, announced spending increases across the board and declared austerity to be over. But these increases must be seen in context: austerity may have ‘ended’ but it is far from undone. And a decade of spending restraint means that even after recent announcements, spending on public services next year will be well below where we might have expected it to be, given historical rates of spending growth and growth in national income.

The fiscal targets bequeathed by former chancellor Philip Hammond all expire during the current forecast period. Moreover, the government has stated that it wants to keep open the possibility of a ‘no deal’ Brexit and, should this occur, it would require an important decision on how fiscal policy should adjust both in the near and long term. These two issues interact since any new fiscal targets ought to be carefully designed so that they are robust to plausible scenarios for the UK economy, not least around Brexit.

Post-financial-crisis, public sector borrowing – the gap between government revenue and spending – has fallen and, at the March 2019 Spring Statement, it stood below its long-run historical average. However, a number of changes have occurred since March, or loom on the horizon.

The global outlook and recent trends in the UK economy point to significant headwinds for growth going forwards. Arguably the most important determinant of the UK’s economic trajectory will be the continuing process of leaving the European Union. Brexit no longer ‘just’ determines future relations with the UK’s largest trading partner and the transition towards them. It has become intertwined with the political outlook and thus broader economic policies, including monetary policy.

The overall outlook for economic growth, and its constituent parts, underpins any fiscal event, with implications for the public finances, public spending, taxation and living standards. Growth in the size of the UK economy – known as gross domestic product or GDP – has averaged 1.3% (on an annualised basis) over the last four quarters. That is somewhat below its potential rate of 1.4% (as estimated by the Bank of England) and the 1.5% growth rate for 2019 that we forecast in last year’s Green Budget, and well below the average of 2.0% per year between 2010 and 2015.

The phase of synchronised growth the world enjoyed in 2017 and early 2018 has come to an end. Following two years when the global economy finally expanded faster than its long-run average of 3.0%, growth looks set to slow to 2.8% in 2019. This is a significant disappointment compared with forecasts from this time last year, which predicted global growth of 3.2% in 2019.

Taxes on motoring raise around £40 billion a year for the exchequer (around 5% of government revenue), equivalent to about £750 per adult in the UK. Most of this comes from fuel duties, which in 2019–20 are expected to raise £28 billion in their own right plus an additional £5.7 billion from the VAT payable on the duties. Another £6.5 billion comes from vehicle excise duty (VED) and £0.2 billion from the London congestion charge.

The new prime minister has expressed a desire to radically overhaul the direct personal tax system. This chapter sets out the impacts of the prime minister’s proposed policies.