BBC Radio Scotland

SNP MP Joanna Cherry, who led the legal challenge to the suspension of Parliament, says she is "cautiously optimistic" the Scottish ruling will be upheld in the Supreme Court.

"I think the Scottish court reached the right decision for the right reasons," she says.

She adds that the Scottish courts were "prepared to look at the issue and the motive" while the English courts "dismissed it as a political question".

But she says "there is a good chance it will progress in the UK court".

"There are a number of legal commentators that take the same view as I do - that the UK supreme court are more likely to prefer the approach of the Scottish court," she adds.

BBC Breakfast

Chuka Umunna, the former Labour MP who left to set up Change UK before again switching party to join the Lib Dems, explains why the party decided to change its official Brexit policy.

Previously, the party had backed another referendum on Brexit - the so-called "People's Vote" - but have now pledged to cancel Brexit if they come to power at the next general election.

Mr Umunna said: "We decide things in this country by reference to the British people, we've done that sometimes by referenda, but usually we've done it at a general election

"And all we're saying is when it gets to a general election that is a public vote where the people have their say, we are putting forward our offer and our suggestion of the trajectory that we go on as a country.

"At that general election we're saying, if we had a Liberal Democrat majority government that would be a democratic mandate empowering us to revoke Article 50 given that that is what we'd put in a manifesto."

Justice Secretary Robert Buckland has also been speaking to BBC Radio 4's Today programme, during which he was asked whether it was conceivable that the PM could suspend Parliament again.

"Harold Wilson said a week is a long time in politics. It seems like an hour is a long time in politics at the moment," Mr Buckland replied.

"For me to sit here and imagine what might happen at the end of October I think is idle."

Tuesday: The appellants in the two appeals to the Supreme Court put forward their cases.

First up it's lawyer Lord Pannick, on behalf of Gina Miller. She wants to overturn the High Court's ruling, which found the suspension of Parliament was lawful.

Then it's Lord Keen, the advocate general for Scotland, on behalf of the UK government. The government is appealing against the Scottish court ruling, which found the suspension of Parliament was unlawful.

Wednesday: The respondents (those who are defending against the appeals) have their chance to reply.

The lawyer for PM Boris Johnson, Sir James Eadie, responds to the Gina Miller case first.

Then it's Aidan O'Neill, the lawyer for the group led by SNP MP Joanna Cherry.

Thursday: There are submissions from those who have been given permission to intervene in the appeals.

Among those making submissions are former PM Sir John Major in the Gina Miller case.

When's the ruling announced? The timing of when the court may rule remains unclear.

Laura Kuenssberg
BBC political editor

Image source, Getty Images

If the prime minister's team and the government machine of a small country can't agree happily on arrangements for a press conference, then it doesn't exactly feel like anyone is in the mood to edge a little bit closer to a Brexit deal.

"Podiumgate", as it has inevitably been labelled, immediately gave a pantomime distraction - complete with a booing crowd - to Monday's developments in the bigger Brexit story.

It's no secret that Luxembourg Prime Minister Xavier Bettel held the views that he was so happy to express.

He has gladly - and candidly - expressed on many occasions his sadness that the UK voted to leave, and his frustration with how UK governments have handled it so far.

But if what happened was an expression of the state of diplomacy between the UK and EU member states, then don't hold your breath for a breakthrough in understanding between the two sides that could lead us all to a new version of a Brexit deal.

Read more of Laura's blog.

Image source, EPA

You can follow the latest developments on the appeals via the BBC News website and a live stream of proceedings on this page from 10:30 BST.

There will also be updates throughout the day on the BBC News Channel and BBC Radio 5 Live.

Today's court hearings are centred around Boris Johnson's decision to suspend - or prorogue - Parliament for five weeks, meaning no debates or votes are held.

New governments normally prorogue Parliament for a short period, but the length and timing - with just weeks until the Brexit deadline - is controversial.

If the Supreme Court judges rule that prorogation is lawful, then Parliament will remain shut until 14 October - unless the government advises the Queen to change the date.

But if the other side wins, it's still unclear how and when Parliament would resume - whether MPs could simply return to the Commons, or if they would need to be recalled by the Queen on the advice of Mr Johnson.

Read more here.

Image source, Getty Images

The Liberal Democrats have been holding their annual party conference in Bournemouth.

While there, the Remain-backing party voted on the party's official Brexit policy, promising to cancel the UK leaving the EU if they win the next election.

Read more here.

It's only Tuesday, but much has already happened this week in Brexit news.

On Monday, Boris Johnson travelled to Luxembourg for Brexit talks with the EU - including European Commission President Jean-Claude Juncker.

He met Luxembourg's PM Xavier Bettel, but Mr Johnson pulled out of the pair's joint press conference, blaming noisy protesters.

Mr Bettel went to on to criticise Mr Johnson's approach to Brexit, calling the situation a "nightmare", saying there were no new serious proposals for a new deal.

But Mr Johnson said he was encouraged by the EU's willingness to engage with the UK in their shared desire to avoid a no-deal exit. He added, though, there had not been a "total breakthrough".

Read more here.

Today Programme
BBC Radio 4

Shadow attorney general Baroness Shami Chakrabarti says the Supreme Court is "highly likely or certainly equally likely to follow in the direction of the highest court in Scotland".

Asked whether the decision is purely "academic", Baroness Chakrabarti says it is an area of "constitutional importance going forward".

"This is a decision that is going to be read for many years to come," she says.

"I know that the court will take that extremely seriously."

With 11 top judges, the Supreme Court has the final say on the UK's biggest legal issues.

The question for the court over the next few days is twofold:

First, do judges have the power to intervene in how a prime minister prorogues Parliament?

And secondly, if they do, was Edinburgh's court right to conclude Mr Johnson had acted unlawfully in closing it for such a long period?

Read more about the Supreme Court and its powers here.

BBC Breakfast

Justice Secretary Robert Buckland is asked about Foreign Secretary Dominic Raab's comments that the government will "test the law to the limit".

Mr Raab wasn't talking about today's court rulings - but about a new law, passed by MPs earlier this month, which is designed to force Boris Johnson to seek an extension to the Brexit deadline rather than have a no-deal Brexit.

Mr Buckland says in response: "I think what the foreign secretary is talking about is the way in which that particular piece of legislation will be used and interpreted.

"It hasn't been used yet, we haven't got to that stage. That stage won't be reached until mid to late October.

"Rather than me speculating about what might happen then, it's better as lord chancellor and justice secretary to remind everybody the rule of law is one of the underlying principles in this country... and respecting that plus the independence of the judiciary is a cornerstone of our constitution."

BBC Breakfast

Asked whether the government will recall MPs to Parliament if the Supreme Court rules the suspension of Parliament is unlawful, the justice secretary, Mr Buckland, says he was not able to go into the "whys and wherefores of what might happen after the ruling".

"It would be wrong of me to anticipate what their lordships might say," he says, adding: "I'd simply say this: We will examine the ruling very carefully and abide by the rule of law."

BBC Breakfast

Justice Secretary Robert Buckland says "of course" he backed the prime minister's prorogation of Parliament.

But he adds the UK's judges are "world class, world leading" and "we must let them do their job".

Whatever their decision is, the "robust independence of the judiciary" must be respected, he adds.

Image source, reuters

Boris Johnson has said he will "wait and see what the judges say" before deciding whether to recall Parliament.

Speaking to BBC political editor Laura Kuenssberg ahead of the court case later, Mr Johnson said he had the "greatest respect for the judiciary", and its independence "is one of the glories of the UK".

"And I think the best thing I can say, having said that, is to wait and see what they say," he said.

Asked again if he would be ready to recall Parliament if that was what the Supreme Court said he ought to do, he said: "I think the best thing I could do is wait and see what the judges say."

The highest court in the UK will start hearing two appeals this morning, over Boris Johnson's decision to suspend Parliament for five weeks during the run-up to Brexit. The hearings are expected to last until Thursday.

The government is appealing against a ruling by Scotland’s highest civil court, which said the suspension was unlawful.

And businesswoman Gina Miller is challenging a judgement by the High Court in London that the suspension was not a matter for the courts.

Follow our live page for the updates.