MPs have been urged to hold their nerve and await the outcome of an unprecedented Scottish legal action before they decide how to vote on Theresa May’s Brexit plan.

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The European Court of Justice has been asked to give a definitive ruling on whether Westminster can halt Brexit, and is due to hear arguments on Tuesday.

The case has been brought by a cross-party group of Scottish politicians led by Green MSP Andy Wightman backed by Jolyon Maugham QC of the Good Law Project.

Also involved are SNP MEP Alyn Smith, Labour MEPs David Martin and Catherine Stihler, Green MSP Ross Greer, and SNP MP Joanna Cherry QC.

HeraldScotland:

As Article 50 is silent on whether it is revocable, the Scottish group asked the Court of Session to refer the issue to the ECJ for an authoritative ruling.

The UK Government fought the case in Scotland and at the UK Supreme Court, but failed to stop it reaching the ECJ.

If the Luxembourg court rules MPs do have the power to order the UK Government to revoke Article 50 without the consent of the other 27 EU nations, it would give the Commons the option of pausing Brexit, rather than face a choice between No Deal and Mrs May’s deal.

Mr Smith, who is expected to attend Tuesday’s hearing alongside Mr Wightman and Ms Cherry, said the UK government was so afraid of the potential outcome, it had mounted “an industrial scale spin operation” to pretend Article 50 could not be stopped.

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He said: “I'm concerned that too many MPs are vulnerable to the ‘there is no alternative’ pressure which will be immense, from business, the UK government and indeed Brussels itself.

“I fear they could buckle.

“There are other options if we look a bit harder.”

Mr Wightman added: “The question as to whether MPs can unilaterally revoke Article 50 is vital, as the chaos around Brexit shows."