THE road to the referendum was marked by milestones - a year to go, the last 100 days, the final month - when we took stock, assessed the campaigns and attempted to predict the result.

Another landmark was reached yesterday. It was 50 days after the historic vote. An odd date to herald, you might think. But why not? It's not as if the constitutional debate has faded into the background, as most of those who campaigned against independence hoped.

Indeed, the first 50 days after the referendum have been dominated by the constitution every bit as much as the last 50 days before it. The Smith Commission, considering further devolution, this week published no fewer than 380 submissions from businesses, charities, trade unions and other civic bodies. The parties' negotiators have been surprised to find themselves attending two round-table meetings each week as the work of thrashing out a new package of Holyrood powers by the end of this month gathers pace. The commission can again expect to hog the headlines next week when organisations give evidence in public to the negotiating teams.

The SNP, meanwhile, is using the period before Nicola Sturgeon's coronation as party leader and First Minister, to discuss its strategy going forward. Ms Sturgeon is preparing the ground to press for a second independence referendum if the UK votes to leave the EU without a majority of Scots backing the decision. Others take a harder line: Jim Sillars wants her to promise a second referendum after 2016 unless devo max is agreed. Angela Constance is campaigning to become SNP deputy leader on a pledge to prepare activists for a second big push.

The post-mortems have begun. Former leader Gordon Wilson suggested Yes lost as it failed to put national identity at the heart of the campaign. Denis Canavan, the Yes Scotland chairman, felt the SNP's currency union proposal was a bigger problem.

The ongoing debate has dismayed a good many on the No side who had hoped to move on from the constitution.

Labour's stand-in leader at Holyrood, Jackie Baillie, has challenged Mr Salmond on his administration's record on health and education in the last couple of First Minister's Questions sessions.

Launching a pamphlet of essays on Scotland's schools on Tuesday, Scottish Conservative leader Ruth Davidson stressed the importance of getting back to bread and butter issues. The Tories are planning similar booklets on health and justice later this year and early next. Both Labour and the Tories have raised serious questions on important issues but they have diverted attention from constitution only fleetingly.

But there are signs the main UK parties have decided they cannot ignore the constitutional debate or confine it to Lord Smith's talks. It will not go away and if they refuse to engage, the terms of the debate will be dictated by the Nationalists. With a battle over the fate of the Smith Commission looming - will its recommendations be seen as a vow kept or a betrayal of pre-referendum promises? - the stakes are high.

Scots Secretary Alistair Carmichael led the charge onto a familiar battlefield: North Sea oil. With the price of Brent crude falling to a four-year low of $82 a barrel, he reckoned it was time to remind us of impact that would have had on an independent Scotland. The Scottish Government, which predicted a price of $110 a barrel, would have had £8.7billion less to spend than it expected, he said, in the first three years after leaving the UK. "That should give us all pause for thought, not least those who favour independence," he went on. "It is increasingly clear that the vote to stay in the stability and security of the UK is the best choice for Scotland."

Alex Salmond was supremely dismissive when the same point was put to him by Tory MSP Alex Johnstone. The price would soon "bounce back" he insisted, before spinning his usual, unfounded line about his opponents treating oil as a "curse and an irredeemable burden". It was an exchange that could just as easily have taken place 50 days before the referendum. In the event it wasn't a bad way to mark the 50-days-after milestone. Constitutional arguments remain at the heart of Scottish politics - and the No side knows it.