A legal challenge to try to prevent Boris Johnson from shutting down parliament to force through a no-deal Brexit begun in a Scottish court this week.
The case is beginning in the Scottish courts because they sit through the summer, unlike their English counterparts.
A group of MPs and peers wants the Court of Session in Edinburgh to rule that suspending parliament to make the UK leave the EU without a deal is “unlawful and unconstitutional”.
Prime Minister Boris Johnson has repeatedly refused to rule out such a move.
Lord Doherty agreed to hear arguments from both sides in September.
However he refused to accelerate the case through the Scottish courts, with the petitioners voicing fears that they may run out of time before the UK is due to leave the EU on 31 October.
The start of the legal action came as it emerged the UK government expects a group of MPs to try to block a no-deal Brexit by attempting to pass legislation when Parliament returns next month.
A No 10 source said they expected the challenge to come in the second week of September, when MPs are due to debate a report on Northern Ireland.
The source assumes the EU will wait until after that date before engaging in further negotiations.
More than 70 politicians have put their names behind the latest Scottish court move, including Lib Dem leader Jo Swinson and SNP MP Joanna Cherry.
A challenge brought by the same group of anti-Brexit politicians last year saw the European Court of Justice rule that the UK can cancel Brexit without the permission of the other 27 EU members.