What impact will the Unite to Remain pact have in the General Election?

The Unite to Remain alliance announced on Thursday – with Lib Dems, Greens and Plaid Cymru standing aside for each other in 60 seats – has been hailed as a triumph of negotiation and cross-party working. But what impact will it have?

Analysis for the Financial Times has found that the agreements are only likely to change the result in Remain’s favour in two seats, compared to 2017.

One of the seats likely to change hands compared to 2017 – Brecon and Radnorshire – is now held by the Lib Dems anyway, after the Lib Dems claimed it in a by-election from the disgraced Tory candidate earlier this year.

The other – Winchester – is currently Tory held but could switch to the Lib Dems after the Greens stepped aside. The analysis is based on the national opinion poll swing from 2017 to now.

The Lib Dems have seen their support surge from just over 7% at the last election to around 16%, with this election seeing a surge in plans for ‘tactical voting’ by Remainers and anti-Tory activists.

In 39 of 59 Unite to Remain constituencies, the ‘pact parties’ lost in 2017 and would lose again now despite the deal, the most extensive constituency polling suggests. They include seats like Witney, Stroud and Wimbledon.

In another 18 seats, a ‘Remain’ candidate is likely to win regardless – including Brighton Pavilion where Caroline Lucas has a strong lead but the Lib Dems have stepped aside, or Plaid Cymru-held Arfon.

However, some seats among those 18 are very close – with Lib Dems only just likely to take Tory-held seats like Wells, Southport and Cornwall North without a pact. That’s because the Lib Dems have seen a big polling boost in their fortunes since 2017.

One political scientist has used a different model to assess the impact of Unite to Remain – with the findings looking much more hopeful for Remainers.

Drawing on individual constituency polling from Best for Britain and collated by Prof Chris Hanretty, Heinz Brandenburg – a political scientist at the University of Strathclyde – says the UTR pact could secure Remainers another 16 seats – taking their tally from 12 to 28 out of the 60 UTR areas.

However, the analysis suggests that – based on constituency polling – there could be another 14 seats which could be taken through a pact but which do not currently have Remain deals in place.

Neither analysis can take into account the effect that parties and campaigners uniting behind one candidate could have on their performance in the weeks to come.

The Unite to Remain deal has come under fire from many Labour figures for including Labour-held seats – with Labour MPs who voted against triggering Article 50 such as Helen Hayes (Dulwich and West Norwood), Thangam Debonairre (Bristol West), and Neil Coyle (Bermondsey and Old Southwark) facing a challenge from the ‘pact parties’.

That means in some places, the pact – despite shifting the party balance of Parliament – could have little effect on the ‘Remain’-ness of the Commons. The deal in Bermondsey could see Neil Coyle’s seat switch to the Lib Dems after the Greens agreed to step aside.

Some left-wing Greens have also challenged the Unite to Remain agreement for primarily working with the Lib Dems – who have failed to condemn austerity after their coalition with the Conservatives from 2010-2015. The party has also refused to work with Jeremy Corbyn, who may Greens believe is closer to the party than Jo Swinson.

The only thing guaranteed with a Remain Alliance is that it’s likely to cause upset within parties – and some voters who feel denied a choice. Parties are damned if they do and damned if they don’t.

Josiah Mortimer is Editor of Left Foot Forward. Follow him on Twitter.