The party manifestos provide few answers about the future of devolution and the Union

While much of the focus on the manifestos has been on the parties’ plans for Brexit and pledges on public spending, what they say about the future of devolution and the Union may have equally significant consequences.

The prospect of Scottish independence hangs over the election

The prospect of a second referendum on Scottish independence has hung over this election. The Scottish National Party (SNP) argues that it already has a mandate, based on its 2016 manifesto, which called for a second indyref if Scotland left the EU against the wishes of Scottish voters.

The SNP is calling for this to take place in 2020. But this timeline is improbable. The Conservatives are firmly against another referendum in any circumstance – with the Scottish Conservative manifesto simply titled No to Indyref2 – and if Boris Johnson is returned with a majority then the SNP will have little leverage. The Liberal Democrats also “oppose a second independence referendum”.

Labour, on the other hand, would oppose independence itself, but has only ruled out a referendum in the “early years” of the next government. This leaves the door open for a vote after the May 2021 Scottish Parliament election, assuming another pro-independence majority is returned. In a hung parliament after 12 December, any Labour–SNP negotiations will centre on this issue.

Pressure for a second independence referendum is unlikely to fade away, especially if the UK leaves the EU. So, the UK government will need a strategy to strengthen and reform the Union, and persuade Scottish voters of the benefits of remaining part of the UK.

Neither Labour or the Conservatives have put forward a clear vision for the future of the Union

However, while both the Labour or Conservative manifestos hint at wider constitutional reform, neither sets out a clear plan to strengthen the Union. The Conservatives’ big idea is a “Constitution, Democracy and Rights Commission”, which will consider the Human Rights Act 1998 and the relationship between government, Parliament and the courts. Reading between the lines, the bruising battles of the Brexit process appear to have encouraged the Conservatives to look for ways to clip the wings of the judiciary and legislature.

The Labour manifesto restates a long-standing promise to set up a UK-wide constitutional convention, led by a citizens’ assembly. However, this headline pledge leaves unanswered some big questions about the scope, purpose and organisation of these initiatives. A more concrete commitment is to replace the House of Lords with a federal-style "Senate of the Nations and Regions", but again there is no further detail on how this would work. In Labour’s Scottish manifesto, on the other hand, there are signs that the party is considering more radical ideas for reform of the Union. There is reference to a “federal system”, founded on principles such as “shared powers”, “partnership” and “subsidiarity”. The fact that these lines do not appear in the main UK manifesto also raises questions about the strength of commitment of the party leadership to this agenda.

Only the Liberal Democrats set out concrete proposals on resetting and strengthening relations between Westminster and the devolved nations. The party proposes new systems to involve the devolved governments in decision making on UK-wide issues such as climate change, drugs, immigration and industrial strategy. There is also a commitment to devolve justice and policing to Wales – a position favoured by the Welsh Labour government, but on which UK Labour remains on the fence.

Both the Labour and Conservative platforms promise very few reforms to the powers of the devolved bodies, except that Labour would devolve employment law to Scotland. Unsurprisingly, the nationalist parties have more ambitious proposals. The SNP calls for drug and migration policy to be devolved to Edinburgh, while Plaid Cymru favours wide-ranging tax, welfare and justice devolution, as well as eventual Welsh independence.

The parties are agreed on the need for devolution within England – but the devil will lie in the detail

Both main parties appear to be planning for further devolution within England. This is welcome – the devolution agenda has fallen down the agenda at Westminster since 2016, yet England remains excessively centralised in its political system and imbalanced in its economy.

The Conservatives promise to publish an English devolution white paper in 2020, with an aim of “full devolution across England”. A detailed vision for devolution will presumably have to await the white paper, but after a period of inaction the Conservatives are at least making a rhetorical commitment to give new momentum to the devolution process – including in those areas of England that have so far missed out.

Labour’s plans are also vague, except for a commitment to the One Yorkshire vision of devolution to the whole historic county of Yorkshire. This is opposed by the Conservatives, who favour a city-region model. Labour also hints at structural reform of the existing devolved authorities at the city-region level, by promising strengthened accountability of elected mayors to local councillors. A further pledge is to recreate the regional government offices scrapped in 2010 – but these operate at a different geographical scale to metro mayors, so it is unclear how these different pledges will fit together.

What neither main party makes clear is what specific powers would be on the table in any future deals that Westminster might strike with England’s cities and regions and, crucially, the mechanisms available to devolved authorities to raise their own revenues.

Whatever happens with Brexit, and whoever wins this election, questions around devolution will dominate the agenda in 2020 and beyond. But with few answers in the party manifestos, it is far from certain how the Union might evolve over the next decade.