A Scottish judge has ruled Boris Johnson's planned suspension of Parliament is lawful and can go ahead, in a boost to the Prime Minister.

Remainer MPs and campaigners launched three legal challenges to Mr Johnson's decision to prorogue Parliament on Thursday next week at the latest.

But the first of those three challenges to be dealt with - that being heard at the Court of Session in Edinburgh - has resulted in a victory for the government.

A challenge in the High Court in London and another in a court in Belfast are yet to be heard.

Remainers do want Parliament to be suspended next week because it gives pro-EU MPs less time to try and stop Boris Johnson's plans to take Britain out of the EU on October 31.

But if the Prime Minister succeeds in calling an election this week, the row over the suspension of Parliament becomes irrelevant.

Scottish judge Lord Doherty has found the planned suspension of Parliament is legal

Lord Doherty ruled this morning: 'In my view the advice given in relation to the prorogation decision is a matter involving high policy and political judgement.

'This is political territory and decision-making, which cannot be measured by legal standards but only by political judgments.

'Accountability for the advice is to Parliament and ultimately the electorate and not to the courts.'

Lord Doherty added: 'I do not accept the submission that the prorogation contravenes the rule of law and the claim is justiciable because of that. In my opinion there has been no contravention of the rule of law.

'The power to prorogue is a prerogative power and the Prime Minister had the vires (powers) to advise the sovereign as to its exercise.'

The decision is a boost for the embattled PM, who is facing another legal challenge in Belfast and a third in London, which is being spearheaded by campaigner Gina Miller and former Prime Minister John Major.

The challenge in Scotland from a cross-party group of 75 MPs and peers argued the decision to prorogue Westminster to reduce time parliamentarians have to scrutinise legislation or attempt to prevent a no-deal Brexit is unlawful.

Joanna Cherry, a Scottish National Party MP who is one of those who brought the case, has vowed to appeal and the case is expected to the end up in the Supreme Court

She tweeted that she will appeal the ruling, which is likely to end up in the Supreme Court

One of the MPs who brought the case in Scotland has already signalled they will appeal the case, with all three lawsuits likely to end up in the Supreme Court.

Joanna Cherry MP, one of those who brought the case, tweeted: 'Seems we have lost #Cherrycase to stop #prorogation at 1st instance. Judge rules court can't review exercise of prerogative power to #prorogue. We thinks he's erred in law on this point & others & will seek to appeal immediately #Brexit #StopTheCoup'

Barrister Jo Maugham QC was also among those supporting the case.

Speaking after the decision, he said: 'The idea that if the Prime Minister suspends Parliament the courts can't get involved loses some ugly demons.

'If he can do that for 34 days, why not 34 weeks or 34 months? Where does this political power end? It's not the law as I understand it.

'Yesterday's hearing was always going to be a bit of a pre-season friendly.

'We're now focused on the Inner House, hopefully later this week, and then the Supreme Court on September 17.'

The barrister for the government, David Johnston QC, said yesterday that the decision was one for politicians rather than the courts

The appeal will be heard at the Inner House, which is the supreme civil court in Scotland.

In a hearing on Tuesday, it was revealed the Government appeared to consider suspending Parliament as early as mid-August.

This was two weeks before publicly announcing the move and despite Mr Johnson's spokesman then claiming any suggestion of prorogation was 'entirely false'.

The ruling in Edinburgh is good news for Boris Johnson, who has insisted the move is not about Brexit, but about a new Queen's speech

A note dated August 15 from Nickki da Costa, a former director of legislative

affairs at Number 10 - which was seen by Mr Johnson and his adviser Dominic Cummings - asked whether an approach should be made to prorogue Parliament, between September 9 and October 14.

A note of 'yes' was written on the document, the Court of Session in Edinburgh heard.

Aiden O'Neill QC, representing the cross-party parliamentarians, said: 'One presumes this was a document sent in the red box to the Prime Minister to be read at his leisure.'

The Queen met the Privy Council on August 28 to approve the move.

Mr O'Neill described Mr Johnson as having a record that was 'characterised by incontinent mendacity, an unwillingness or inability to speak the truth'.

Responding for the Government, David Johnston QC, said: 'The proper forum for these matters to be scrutinised is the political forum.

'Those who make decisions that don't go down well in the political forum will

be held to account there - either in Parliament or, ultimately, by the electorate.'