The coalition was an unfamiliar political arrangement in Britain, and against a background of economic crisis and a record budget deficit, many speculated that it would be short-lived. Yet the coalition provided a stable government for a full five-year term, managed a partial recovery in government finances and oversaw a faster rate of economic growth than any other G7 country at that time.

Key Liberal Democrat policies from the party’s 2010 manifesto were implemented: a significant rise in the income tax threshold took an estimated three million low-paid people out of tax altogether; the ‘pupil premium’ provided more resources for schools to teach children from deprived backgrounds, and significant investment was made in renewable energy. Liberal Democrat influence led to increases in the state pension, a higher priority to mental health, legislation for same-sex marriage, the development of an industrial strategy, the creation of the world’s first Green Investment Bank, and an expansion in the apprenticeship programme. Also, Liberal Democrat ministers blocked or ameliorated Conservative proposals that would otherwise have adversely affected workers’ rights, disability benefits, support for young people and immigration. They also blocked a referendum on EU membership, and extensions to covert surveillance – policies that were promptly reinstated by the Conservative government elected in 2015.

The party’s constitutional reform agenda saw major failures, however, with a change in the voting system being blocked by referendum defeat in 2011, reform of the House of Lords by a Conservative rebellion in 2012, and party funding reform by Conservative ministers’ desire to protect their donors. Offsetting these disappointments were the introduction of fixed-term parliaments and the devolution of greater powers to Scotland.

The challenging economic climate, and the Conservative Party’s austerity programme, meant that difficult compromises had to be made. Liberal Democrat ministers fought, often successfully, to slow down or reverse cuts in public services and to soften their impact, but this work was not generally visible to the electorate. Particularly damaging was the raising of university tuition fees, which led to a disastrous loss of trust in the party and its leadership, because the party had consistently campaigned against such fees, and in the 2010 election all Liberal Democrat candidates had pledged to vote against any rise.

Support for the party fell sharply. Between 2011 and 2015 every round of local elections saw hundreds of Liberal Democrat councillors lose their seats, and Liberal Democrat members were toppled in elections to the Scottish Parliament, the European Parliament, and finally in the 2015 general election. For five years, the Liberal Democrats had proved that they could handle power competently, but their efforts and successes had been inadequately communicated to the public and were swamped by the false perception that the party had colluded wholesale in a Conservative agenda. In addition, during the 2015 election campaign fears of a Labour and Scottish Nationalist coalition in the event of a hung parliament swayed many voters towards the ‘safer’ option of a Tory vote, and the Conservatives won with a small overall majority. The Liberal Democrats shrank from 57 MPs in 2010 (with 23 per cent of the vote) to eight in 2015 (with just 7.9 per cent of the vote).

Could the party have handled the coalition better? The debate continues, but the party’s experience of a fall from favour mirrors that of other smaller partners in coalition governments across Europe.