Can a Remain alliance rally anti-Brexit voters during the general election?

Liberal Democrats, Green Party and Plaid Cymru candidates are expected to step aside in each other's favour in key constituencies, writes Andrew Woodcock

There is no guarantee that voters whose preferred party decides not to stand will obediently follow its advice on who to back (PA)

An announcement is expected within days over a so-called Remain alliance for the 12 December election between parties committed to keeping the UK in the European Union.

With 48 per cent of voters backing Remain in the 2016 referendum, and opinion polls over the past two years consistently finding that more than 50 per cent now want to stay in the EU, it might be thought that an alliance of this kind would wield near-unstoppable power in a general election.

But the complex web of party allegiances and rivalries, coupled with the UK’s first-past-the-post electoral system, means it is not so simple.

Few observers believe that cooperation between the parties will have a decisive impact on the outcome of the election. The first question, of course, is what constitutes a Remain party?

Only Liberal Democrats, Greens, Plaid Cymru and the Independent Group for Change – each committed to future EU membership – are thought to be involved in talks arranged by the Unite to Remain group.

Labour’s position that it would negotiate a new Brexit deal before putting the decision to the electorate in a referendum mean that it cannot be considered a Remain party.

And rivalries between the staunchly pro-EU Scottish National Party and Liberal Democrats have stood in the way of the involvement of Nicola Sturgeon’s party.

There is therefore a limit to the impact that this alliance of smaller parties can have.

But they believe that in certain key seats, they can repeat the success of the recent by-election in Brecon and Radnorshire, where Lib Dem Jane Dodds won by 1,400 votes after Plaid and the Greens stood aside.

A Remain alliance helped Liberal Democrats win Brecon and Radnorshire (Getty)

Liberal Democrats have already indicated that they are willing to make way for Greens in their two most-favoured constituencies of Brighton Pavilion, where former leader Caroline Lucas has been MP since 2010, and Isle of Wight, where the environmentalist party took 17.3 per cent of the vote in 2017.

And there are several seats in Wales – such as Ynys Mon (Anglesey) – where Lib Dems could give Plaid a clear run.

Jo Swinson’s party has also made clear it is ready to stand aside in Beaconsfield, where the former Tory attorney general and prominent anti-Brexit campaigner Dominic Grieve, is fighting to retain his seat as an independent.

And they could also decide not to fight Broxtowe, to boost the chances of Independent Group for Change leader and former Tory MP Anna Soubry.

Reports suggest that a Remain alliance arrangement could be put in place in as many as 60 out of 632 mainland British seats – a large number of which are likely to involve Greens standing aside to give Lib Dems a better chance of defeating Tories or Labour.

However, in many of these, even if the parties involved could rally together all their combined support from the 2017 election, they would still fall well short of victory.

In Ynys Mon, for example, adding the 1.3 per cent gained by Lib Dems last time round to their own tally of 27.4 per cent would still leave Plaid more than 10 points short of claiming the seat.

On the Isle of Wight, the combined total of Lib Dem and Green votes would not have been enough to secure second place in 2017.

And there is no guarantee, of course, that voters whose preferred party decides not to stand will obediently follow its advice on who to back instead.

The hope of many of those involved is that by identifying one candidate clearly as the representative of Remain, they can tempt the many supporters of EU membership who would otherwise vote Labour or Conservative.

A tactical voting website run by the pro-referendum campaign Best for Britain has been criticised for advising Lib Dem votes in some seats where Labour is the incumbent or a close challenger to Tories, such as Kensington, where Emma Dent Coad is clinging on to a majority of just 20.

Meanwhile, the limitations of the strategy where exposed when Ms Swinson was accused of splitting the Remain vote in Canterbury by deciding to run a Lib Dem candidate against pro-EU Labour MP Rosie Duffield, who holds the seat by just 187 votes over Conservatives.

Even if the parties can unite behind a single candidate in as many as 60 seats, it seems unlikely that a Remain alliance will have more than a marginal impact on the overall election result.