The Liberal Democrats are likely to withdraw their candidate in Arfon for the General Election after agreeing a ‘pro-EU electoral pact’ with Plaid Cymru and the Green Party.

The pact means that candidates will stand aside for each other in 11 of the 40 seats in Wales, to increase the chances of a Remain-supporting MP being elected.

Liberal Democrats and Greens are likely to stand aside for Plaid Cymru candidates in three of the four seats Plaid is defending in the December election – Arfon, Dwyfor Meirionydd and Carmarthen East and Dinefwr.

Plaid held Arfon in the 2017 General Election by just 92 votes, the closet marginal seat in Wales.

Labour are expected to annonuce a new candidate soon from an all female shortlist, after Mary Gwen Griffiths Clarke, who stood for Labour in Arfon for the 2017 General election, announced earlier this week that she is standing down from politics to focus on her legal career.

After May’s EU Parliamentary elections, Plaid Cymru leader Adam Price AM wrote to several pro-Remain parties, including the Lib Dems and Green Party, calling on them to work together in a snap general election or second EU referendum. The discussions that led to this electoral pact stemmed from that letter.

On Sunday, Plaid Cymru’s Helen Mary Jones AM said she was “not entirely comfortable” with electoral pacts but they were the “right thing to do” for the 12 December general election.

A Welsh Labour spokesperson said: “This pact appears to be nothing more than Plaid and the Lib Dems propping each other up in seats they’re worried about losing. Plaid are worried about Arfon. The Lib Dems don’t think they’ll hold Brecon & Radnorshire.

“Both will fight it out over Ceredigion because it’s not really an alliance, it’s two parties looking out for their own self interest.

“If people want the final say on Brexit they should vote Welsh Labour, and in that public vote we will campaign to Remain.”

Plaid gained Arfon in 2010 and held it in 2015; their victory in 2017 was the narrowest margin in Wales for the election.

The General Election will be held on 12 December 2019.