In rounding off his argument, Mr Eadie makes what sounds like an appeal for common sense to prevail.

In passing other judgements, he says the Supreme Court has had regard to concerns about the "law reaching conclusions that the ordinary man and woman on the street simply would not understand".

He says this rule should be taken into account regarding Brexit: "If you asked the ordinary man or woman on the street if they regarded the fact that a referendum has occured as remotely relevant to the question of whether the government can give Article 50 notice, the answer would be 'of course it is'".

Mr Eadie says his case is "on track" and it might be a convenient moment to break up for the day. 

Lord Neuberger agrees and says the court will reconvene as close as possible to 10:15 GMT on Tuesday morning. 

As today's session draws to a close, Mr Eadie is summarising his main arguments about the exercise of the government's executive powers.

He says Parliament has "conspicuously refrained" from making any provision for controlling the use of the government's prerogative powers to withdraw from EU treaties or the steps leading up to withdrawal. 

At this point, Lady Hale intervenes to say Parliament has legislated to control the exercise of the prerogative in relation to the withdrawal of other countries from the EU in terms of the inclusion of Article 50.

Mr Eadie concedes that Lady Hale is right.

For the government, James Eadie now moves on to the crucial question of whether the EU referendum was binding, or advisory only. 

He is asked by one of the justices about a briefing paper produced by the House of Commons library which suggested that the referendum was merely advisory.

Mr Eadie notes that the House of Commons was concerned about the document - which was produced by the parliamentary authorities and not sanctioned in any way by the government - being raised in court but that it had been referred to during the High Court hearing and therefore "that horse may have bolted".

He says the phrase advisory could be regarded as "neutral" depending on how it was interpreted, but refers to a statement made by then foreign secretary Philip Hammond during the referendum bill's passage that the vote would be "decisive".

There has been plenty of discussion in recent moments about the constitutional status of the 1972 European Communities Act and the laws that have succeeded it - with Mr Eadie suggesting they should all share the same constitutional force.

James Eadie brings us right up to date by focusing on the 2015 EU Referendum Act, which authorised this year's vote, saying it is "highly improbable" that the government went to great lengths to table and pass the bill if it intended to "reserve the right" of Parliament to revisit the issue later. Here is his full quote.

James Eadie is addressing in depth Parliamenty's scrutiny of the 2008 Lisbon Treaty - which introduced the current Article 50 framework and two-year negotiating period for members wishing to quit the EU. 

He asks what "species of control" MPs and peers intended to exercise over the UK government's powers re Article 50 when they ratified the treaty. 

Dominic Casciani
BBC correspondent at Supreme Court

The government argues that the royal prerogative - British legalese for executive power - means that ministers have “from time to time” changed the EU package without needing Parliamentary approval to do so. 

But when Mr Eadie argued a short time ago that the power extended to changing “from time to time” whether the UK was actually a member without bothering to ask Parliament, he got some stiff questioning from four of the justices. 

Lord Mance said there was a “huge difference” between the power to change the rules of a club one was a member of - and not being a member of the club at all. 

And Lord Reed said the “difficulty” with the government’s argument was that it was making Parliament “redundant”. 

If the Supreme Court rules that only Parliament has the right to trigger Article 50, this may turn out to have been a key battleground.

For the government, Mr Eadie says it is wrong to characterise the invoking of Article 50 as "revoking or over-riding statutory rights" stemming from membership of the European club which have been in force in UK law for decades.

These rights will simply, in his words, "expire" as envisaged by the 1972 European Communities Act (ECA) which took the UK into the EU.

The ECA drawn up by the government of Edward Heath had a "limited purpose", he adds, which was to implement treaty obligations entered into by the UK rather than to guarantee rights arising from those treaty obligations. 

To make the point, he says the ECA did not guarantee the right of the UK citizen to live in France as this would clearly be a matter for the French government. 

An investigation is under way into the leaking of a letter warning against leaks, No 10 says.

ITV

House of Commons
Parliament

Labour MPs Kate Green and David Hanson ask Amber Rudd whether the government intends the UK to be a member of Europol, external once the country has left the European Union.

The home secretary responds that the UK has recently opted in to the new elements of Europol, and says that the issue is part of the ongoing negotiations.

"When people voted to leave the EU they did not vote to be less safe," she says.

There is more of a sense of a free-flowing discussion between Mr Eadie and the justices now and of the eminent QC being cross-questioned.

At one point Lord Neuberger intervenes to urge one of his colleagues to allow the lawyer to finish his answer. 

The government lawyer repeats his view that domestic UK rights are "susceptible to change at an EU level by exercise of government action", saying that to use a more "emotive" phrase, these rights can be "destroyed".

He says, in theory, 99.9% of domestic rights could be removed under the UK's prerogative powers. Lord Mance takes issue with this, saying the chance of the Council of Ministers and European Commission agreeing to this is "rather remote" and that the UK would probably find itself being outvoted. 

He makes an interesting analogy, saying a distinction must be drawn about members of a club having to comply with changes in dress code and members either being expelled or giving notice of their intention to leave.

Mr Eadie accepts there is a distinction between withdrawing from an organisation and abiding with the "corpus of rights" as they change.

Lord Carnwath says he does not know why the government lawyer is spending so much time on the original 1972 European Communities Act when the provision for EU exit was changed so dramatically by the 2009 Lisbon Treaty.

The Daily Mail

The Daily Mail is describing today's court case as the "Battle of Britain"., external

Chief reporter, Martin Robinson, claims four of the 11 judges have formal links to the EU or linked institutions and that five have publicly expressed views which appear sympathetic to the EU and its aims.

And one of their columnists, Guy Adams, said the US "puts us to shame" as their Supreme Court judges are appointed more publically. 

He wrote: "As a result of this secretive process, we now have a Supreme Court which is 91 per cent male, 100 per cent white and 81 per cent public school and Oxbridge-educated.

"More importantly, given the sway it will hold this week over the future of the nation, it is a court run by people whose motivations, legal outlook, and political allegiances remain largely a mystery to everyone apart from themselves."

Dominic Casciani
BBC Correspondent at the Supreme Court

James Eadie QC has been stating over and over that the power to make and break treaties lies with ministers - even if those international agreements include creating or ditching citizens’ rights. 

He argued that as Parliament has not explicitly removed ministers’ “prerogative powers” to leave the EU, the power to trigger Article 50 is with ministers alone. 

Two things stand out. Mr Eadie argued - to some surprise in court - that Parliament had been “neutral” whether or not the UK actually joined in 1972 even though it had passed an Act to do so. He argued that the 44-year–old law was merely translating the government’s decision into law. 

Secondly, there was a big but simple question from Lord Wilson shortly after lunch: If accession was a result of joint effort by Parliament and the executive (ministers signing the treaty and Parliament embedding that into law) shouldn’t our exit be so too? Mr Eadie said no. 

Lord Carnwath picks Mr Eadie up on his earlier point that Parliament will still be heavily involved in the Brexit process through the Great Repeal Bill - which is intended to transpose EU legislation since 1972 into domestic law before Parliament decides what to retain and what to jettison. 

He asks what evidence there is for this and asks the lawyer to elaborate on what the proposed bill is, what it will do and what ministers have said about it.

For a small moment, the government lawyer looks a little flustered and says "pass, I will double check", adding that he thinks there was a mention of the bill at the Conservative Party conference. 

Mr Eadie is being pressed rather more forcefully about his case now, in a series of exchanges with a number of the Supreme Court justices.

There is a sharp exchange between Lord Sumption and Mr Eadie, in which the government lawyer respectfully suggests he is being asked a similar question to one posed before the lunch break about whether he is getting the sequence of statutes relating to the royal prerogative in order and starting in the "right place". 

The justice replies: "It is another possible instance of your perhaps starting in the wrong place."