Today Liz Truss becomes the UK’s fourth Prime Minister in just over six years. She will be the third female Prime Minister in the country’s history (after Conservatives Margaret Thatcher and Theresa May).

Earlier this summer, Conservative members of Parliament (MPs) toppled incumbent Prime Minister Boris Johnson. First they forced a Tory MP confidence vote on his leadership, which he survived. Soon after, a slew of high-profile Cabinet resignations made his position untenable.

Notionally, the triggers were revelations of several COVID-19 related lockdown breaches and then a government sex scandal involving one of the party’s whips. Yet there was dissatisfaction bubbling with Johnson from his backbenches on various policy topics even before this. The Prime Minister resigned.

His decapitation started a torturously long Conservative leadership contest, with 11 MPs declaring their candidacy, and 8 being formally nominated, before this group was whittled down to just two through successive rounds of voting by Conservative MPs.

Truss proceeded each time and ultimately found herself up against former Chancellor Rishi Sunak in the final run-off. This culminated in a full ballot of ordinary Conservative Party members across the country. She emerged victorious today with 57% of the vote and will become party leader and, so, Prime Minister, given the party’s “working majority” of 73 seats in the House of Commons.

The central cleavage of the leadership campaign against Sunak was on taxation and borrowing. Sunak argued that new health and social spending, COVID-19 debts, and inflation all justified raising taxes permanently in the name of fiscal responsibility.

As Chancellor, he had increased the employee and employer national insurance rates (a bit like social security contributions), frozen income tax thresholds, and set in train a rise in the headline corporation tax rate from 19 percent to 25 percent. The UK’s overall tax burden relative to GDP was due to rise to its highest level since World War II.

Truss argued that this would suffocate economic growth, and so pledged to cancel the corporation tax increase and reverse the national insurance rate hikes. She would tolerate higher government borrowing in the short-term, although committed to keep the growth rate of government expenditure below GDP growth over the medium term. Sunak warned of higher interest rates with her extra borrowing; Truss said his tax-raising plans would kill the incentives for a recovery. Tory members were more convinced by the latter.

Truss is a free-marketeer and delivered a wide-ranging speech on economics at Cato in 2018. Her daughter is named “Liberty.” Her writings before entering government show she is a supply-sider in the broad sense of wanting to remove government barriers to free economic activity and lifestyle freedoms. She criticized the UK’s restrictive land-use planning system, argued for reining in the regulatory state, and was hawkish on government spending, especially as leader of the “Free Enterprise Group” caucus of Conservative MPs.

As trade secretary, she oversaw the development of new free trade agreements with Australia and New Zealand and pushed for the UK to enter the Asia-Pacific CPTPP as the UK restored its independent trade policy after Brexit.

Though a Remainer in the 2016 Brexit referendum, she quickly embraced the Leave result, and has talked about diverging from Brussels on issues where the EU’s regulatory instincts are highly precautionary. In recent months, her team have mused on the possibility of changing the Bank of England’s monetary mandate from a 2 percent inflation target to a nominal GDP target.

As foreign secretary, Truss has been very hawkish on Russia and strongly favored extensive sanctions on the country following the Ukraine invasion. Largely as a result of that conflict, though, Truss will be stepping into an economic crisis. Headline inflation in the UK was 10.1% in July. A sharp rise in energy prices is threatening a deep recession.

As the chart below shows, the huge spike in the wholesale gas price has seen UK households’ (and businesses’) energy bills skyrocketing and they are projected to continue on an upwards trajectory. The increase is so large that it seems inevitable Truss’s government will reach for some policy intervention to protect the worst-affected households and businesses. An early test of her liberalizing bonafides is whether Truss can use this crisis to persuade the country to permit fracking for natural gas and other supply-side liberalizing measures to lower living costs.

Whatever Truss’s personal convictions on economic policy, the UK has a more collective style of government and the politics of the moment are unlikely to lend themselves to a major shrinking of the state.

Boris Johnson won the 2019 election with a massive majority, eating into Labour’s traditional “Red Wall” heartlands, in part by promising major infrastructure projects and more money for public services. Truss has pitched that she can keep that electoral coalition together. Although she advocates for more market-based means of reviving these industrial heartlands than Johnson, her pivoting to major spending cuts, especially without a general election victory, is unlikely. Without that sort of electoral mandate, she would struggle to get any contentious legislation through the House of Lords.

That said, there are plenty of smaller policy changes that a Truss government could make on the regulatory front to enhance freedom and opportunity immediately. UK growth has been pathetic since the financial crisis in 2008. The UK is now around 30 percent poorer than the U.S. in per capita terms and has 15 percent lower productivity per hour. This suggests that better supply-side policy could still have a big impact on living standards.

The UK must have a general election by January 2025 and, currently, the Conservatives trail Labour in the polls. That leaves Truss a narrow window of time to oversee a change in economic fortunes and to make her mark on the contours of the British state.