Judges in Scotland's highest civil court will not rule on a legal bid aimed at forcing Boris Johnson to ask for a Brexit extension if a deal is not agreed by next week.
The Prime Minister is required to ask the EU for an extension by October 19 to prevent no-deal under the so-called Benn Act which was passed by MPs.
However the Court of Session announced it would not make a ruling until October 22, after the October 19 deadline.
Campaigners asked the Court of Session in Edinburgh to use a unique power of "nobile officium" which would have allowed an official to send a letter on behalf of Mr Johnson if he refused.
Mr Johnson has continually said the UK will leave the EU with or without a deal by the October 31 deadline.
The likelihood of securing a deal with the EU is becoming increasingly difficult after German Chancellor Angela Merkel shot down Mr Johnson's plans.
Irish leader Leo Varadkar also poured cold water on a Brexit extension, saying it would be "very difficult".
Mr Johnson will hope to gain concessions from Irish Taoiseach Leo Varadkar during in-person talks anticipated later this week.
But with the October 31 deadline rapidly closing in, Mr Varadkar warned of the challenges of securing a new deal by next week – a key period in the Brexit saga with the summit in Brussels.
The Irish premier said Ireland and the EU would not accept an agreement at “any cost”.
“There are some fundamental objectives that haven’t changed for the past three years and we need them guaranteed,” he told RTE news.
“I think it is going to be very difficult to secure an agreement by next week, quite frankly.
“Essentially what the United Kingdom has done is repudiate the deal that we negotiated in good faith with Prime Minister (Theresa) May’s government over two years and sort of put half of that now back on the table and are saying: ‘That’s a concession’.
"And of course it isn’t really.”