LONDON (REUTERS) - Britain's smaller pro-European political parties have announced a "remain" electoral alliance in which they will step aside for each other in 60 constituencies in the upcoming election to deny Prime Minister Boris Johnson a parliamentary majority.
The pact between the Liberal Democrats, the Welsh nationalists Plaid Cymru and the Green Party, along with some independent lawmakers, aims to give a free run to just one candidate in each constituency who wants to overturn the decision to leave the European Union.
Britain is heading towards a deeply unpredictable general election on Dec 12 that could decide the fate of its planned departure from the European Union.
Ms Heidi Allen, a former Conservative lawmaker who joined the Liberal Democrats, said the cross-party alliance was the first in a British national election in more than a century.
The parties "know this general election is the last chance to change the path that this country is currently on", said Ms Allen, who was involved in organising the pact.
The first December election in Britain since 1923 is one of the hardest to forecast in years. Brexit may well trump voters' traditional left/right loyalties and give smaller rivals a chance to challenge the two biggest parties: Mr Johnson's Conservatives and the left-leaning Labour Party.
Most polls so far have the Conservatives ahead - a YouGov poll this week had them leading Labour by 11 percentage points.
The template for the cross-party deal was a local election in Wales earlier this year, when the Liberal Democrats seized the seat from the Conservatives after Plaid Cymru and the Greens did not run candidates.
However, the alliance does not include the Labour Party or the Scottish National Party, which will blunt its effectiveness because they currently have the second and third-most MPs and support another Brexit referendum.