Salmond tied by a 'sunset clause' over timing of poll

As home and foreign media turn their attention on the landmark agreement, which is likely to be dubbed the St Andrew's House Accord, a difference of emphasis between the two governments on presentation appears to be emerging.

It is thought that David Cameron is approaching Monday's event as significant, but wholly domestic, while Alex Salmond will treat it as a far more international and diplomatic event.

As with traditional summits, all of the detailed work has been done by ministers and officials before the two leaders meet, so that all that the Prime Minister and First Minister have to do is present a united front, smile for the waiting media and put pen to paper – barring, that is, any unforeseen last-minute glitch.

While certain presentational details still have to be ironed out, the Union flag and Saltire are expected to flank the two leaders as they sit down at a table in front of the television cameras to sign the document, said to be no more than a few pages thick.

The Scottish Secretary and the Deputy First Minister, who have had several negotiating sessions during the past few weeks, will also sign the agreement, which will take the form of a memorandum of understanding, setting out details of the so-called parliamentary Section 30 Order as well as others that cover issues such as the role of the Electoral Commission.

Mr Cameron will arrive in Edinburgh after earlier having taken part in a business-related visit and will, after the signing ceremony, say a few words to the waiting press before getting into his limousine and heading back to London.

In contrast, Mr Salmond is expected to hold a full press conference with the scores of reporters from home and abroad, who will be covering the event.

One Coalition source described the signing of the intergovernmental agreement as a "significant milestone", leading to the "biggest decision in Scotland for 300 years".

Another source insisted no-one within the Coalition was trying to minimise the significance of the event but added: "This is not an international treaty with a foreign country: Scotland has two governments."

Last night, after Mr Moore and Ms Sturgeon had completed their final round of talks, they issued a joint statement, which said: "We have resolved the issues that remained outstanding between us and reached a positive conclusion to our discussions. The full agreement, including the terms of the Section 30 order, will now go to the First Minister and the Prime Minister for their discussion and approval."

The final details involve "tidying up" the text and agreeing funding arrangements for the campaign.

The Herald has been told by a key player that at no time during the many weeks of talks was the process ever at risk and that the mutual respect on both sides, which involved a complete news blackout, had paid off.

The Secretary of State said: "I would like to thank Nicola Sturgeon for the constructive manner in which she has conducted these negotiations over recent weeks.

"I am confident this agreement will be approved by the Prime Minister and First Minister on Monday and that Scotland will have a legal, fair and decisive referendum to decide whether we remain part of the United Kingdom."

He added: "I relish the prospect of getting into the real debate over Scotland's future and putting our case to the Scottish people on why their best future lies as full members of the UK family."

Elsewhere, Ruth Davidson, the Scottish Conservative Party leader, also welcomed the agreement and said she now looked forward to having the debate about the substantial issues regarding independence.

She said: "Scotland is facing its biggest decision in 300 years and people need to be able to make an informed choice.

"That means politicians from all sides, including the SNP, answering the important questions put to them by the people of Scotland."