THE SCOTTISH Greens will contest the next UK general election as a de facto referendum on independence if no legal route to a Holyrood vote emerges.

The pro-independence party has joined the SNP and Alba in pledging to treat the next Westminster election as a single-issue poll on separation if the Supreme Court states that the Scottish Parliament does not have the authority to hold a referendum.

Nicola Sturgeon has set out the Scottish Government’s strategy to hold a referendum in October next year, subject to the UK Supreme Court ruling it is within devolved competency.

If no legal routes exist, the First Minister said the SNP will treat the next UK general election as a ‘de facto referendum’ on independence and would begin negotiations over separation with the UK Government if pro-independence parties signed up to the idea won the popular vote in Scotland.

Alex Salmond’s Alba party had already backed Ms Sturgeon’s de facto referendum fall-back plan.

Now, the Scottish Greens have also signed up to the strategy.

At a meeting of the Greens’ national council this afternoon it was agreed the party will aim to stand candidates in every constituency in Scotland.

Commenting in a statement, Scottish Green Party co-leaders Patrick Harvie and Lorna Slater said: “The people of Scotland have repeatedly returned pro independence majorities to Holyrood and Westminster. They must have their say.

“Our preference is still for a referendum to take place in October 2023.

"Should that prove impossible, then we will contest the next UK General Election as a de-facto referendum.

“In that circumstance we want to put the unique Green case for independence to every voter in Scotland. And every vote cast on that basis will count as a vote for Scotland to become a Green and independent country.”