A cross-party group of MPs and peers has said it is planning legal action in Edinburgh to prevent parliament being “closed down” in the run-up to Brexit.
It will go to the Court of Session seeking what is called a declarator that the prime minister cannot lawfully advise the Queen to suspend parliament.
Backers include parliamentarians from Labour, the SNP, the Liberal Democrats, Plaid Cymru and the Green party.
They have written to to Lord Keen, Advocate General for Scotland.
The legal team taking the action on behalf of the parliamentarians has had previous success, when it established that the UK had the power to revoke Article 50 – the mechanism which started the Brexit process.
That ruling was challenged, unsuccessfully, by the UK government at the Supreme Court and the European Court of Justice.
The latest action is likely to begin at the Court of Session – Scotland’s highest civil court – next week.
Its backers hope to have the Court of Session’s decision before parliament returns from its summer break.