SO who blinked first?

David Cameron or Alex Salmond?

After Coalition sources at the weekend flagged up the desire for Holyrood to hold a referendum by the summer of 2013, arguing the delay was damaging Scotland's economy, it was hastily flagged down by Monday.

A sign of weakness by the Prime Minister in the face of Nationalist indignation perhaps?

Then, on the second day of high constitutional drama yesterday, the First Minister, who popped up on television to declare in no uncertain terms that his Government would not be dragooned into holding an independence referendum on Westminster's terms, quite unexpectedly announced he wanted to hold it in the autumn of 2014.

Was this a first ministerial cave-in under Coalition pressure?

Whoever blinked first, the reality is that the constitutional battle for Scotland's future has now well and truly been engaged.

While the SNP Government laid out its timetable towards a referendum in the autumn of 2014 with a consultation to follow, the Lib-Con Coalition put forward its "helpful" proposals with its own consultation on how Westminster could empower Holyrood to hold a legally-binding poll.

The First Minister insisted a referendum had to be "made, built and run in Scotland" and the political reality was the SNP's mandate to hold a referendum on independence was "unanswerable".

But, one has to ask, will we ever get there because Westminster, the authority on constitutional matters, disagrees?

Earlier yesterday, the UK Government set out what it believes is the legal position.

This is, as things stand, that the Scottish Parliament does not have the power to hold even a consultative referendum, never mind a legally binding one. Whitehall sources claimed that if it tried to stage one, it would amount to nothing more than an "opinion poll".

Yet they went further and posited the nuclear option – that if Holyrood began a legislative process to put a bill through the Edinburgh Parliament to hold a referendum, Westminster would instruct its lawyers to seek a court order stopping it.

The irony is that, because these are constitutional matters, then the court in question would be the UK Supreme Court; Mr Salmond's favourite institution (not).

Now some might say this will never happen but at the moment Westminster and Holyrood are still very much at odds.

With a deal of glee Coalition sources said the naming of autumn 2014 by Mr Salmond was the "first contribution" to Westminster's consultation exercise. "It's good that he has reacted," said one.

Another also claimed the First Minister had accepted the way forward was for Westminster to instigate what is known as a Section 30 order, enabling Holyrood to hold a legally binding poll.

Yet, the Coalition has already stuck strings to it, including that there should be one yes-no question, no 16 or 17-year-olds should take part, as the SNP wants, and the Electoral Commission should oversee the poll, which the SNP does not want.

While the UK Government has stepped back from its insistence that a referendum should be within 18 months and now says a timescale should be part of the consultation, in reality it still believes 2014 is much too late.

On the flip side, the Scottish Government insists it has the political mandate as well as the legal competence to push through a bill to hold a consultative referendum on Scottish independence.

Edinburgh sources said Mr Cameron's "Thatcherite behaviour towards Scotland" had backfired and that if Westminster sought to stop any Holyrood referendum bill in its tracks, then this would be a "massive miscalculation".

Will the naming of autumn 2014 satisfy most Scottish voters or will they think Westminster's drive to have a poll sooner is reasonable?

Then again, it could be that we might now be into constitutional bargaining territory: Holyrood says autumn 2014, Westminster says autumn 2013 and we end up somewhere in the middle.

Yet the stakes are high and things could turn nasty.

The Westminster consultation lasts only until March 9 after which Mr Cameron and his colleagues will have to decide what to do.

If Mr Salmond and his colleagues continue to dig their heels in and decline to accept the attached Westminster strings, then the constitutional battle engaged in the last 48 hours could transmogrify into a full-blown constitutional crisis, which is played out not on the streets of Scotland but in the lawyerly surroundings of the UK Supreme Court in SW1.