We will never know if, or how, the "vow" to deliver more powers to the Scottish Parliament, made on September 16, influenced the outcome of the referendum.

Those who would have liked the devo-max option on the ballot paper may have taken heart and voted No. For many others, on either side of the debate, this was at best a distraction.

Beyond the cognoscente, it's a safe bet that not many realise exactly which powers rest at Holyrood at present, far less which ones are in the pipeline. Responsibility for health, education, law and order, and many other areas is devolved. Stamp duty, land tax and land transaction tax will be devolved next year and limited income tax powers will become effective in 2016. Further powers will follow and should be on the statute book early in the next parliament, regardless of who wins the General Election.

Earlier this year, months before the referendum, the Labour, Conservative and Liberal Democrat parties unveiled their proposals. They did not agree on detail and the pre-referendum "vow" did not change that.

What the "vow" did was set out a clear timetable for the newly appointed commission, under the chairmanship of Lord Smith of Kelvin, to find a consensus on the different proposals with a view to a White Paper being published by the end of November and draft clauses for a new Scotland Act by Burns Day next year. With a fair wind, the act could have a second reading in the first legislative week of the new parliament session in June.

Lord Smith will have his work cut out, but, if all the parties focus on delivery, they could meet the timetable. They are not starting with a blank sheet of paper but a 14-point plan for "new powers" set out by Gordon Brown, the driving force behind the "vow" initiative during the referendum campaign.

Now Mr Brown is on the warpath, furiously accusing David Cameron of trying to scupper the negotiations before they get off the ground. Indeed, in the immediate post-euphoria of the referendum result Mr Cameron injudiciously linked the delivery of more powers to the issue of English votes for English laws, but he has backtracked and given a categorical assurance in public and private that the delivery of Scottish powers will stand alone.

Mr Brown is urging people to sign a petition to force the Prime Minister to deliver his pledge on extra powers for Holyrood, "no strings attached". It seems a rather futile exercise since Mr Cameron has promised repeatedly to do just that.

Mr Brown's colleagues are perplexed at his unilateral attack, wondering why he has left himself open to the scorn of his political opponents. He may have missed David Cameron's recantation or is it possible that hostility to his successor as Prime Minister has clouded his judgment? But it is also possible he fears the final consensus will not be his preferred choice.

The proposals on the table include more control over investment, job creation, welfare, transport, elections and taxation and, while there may be points of debate within each category, it will be taxation that will be the most difficult to square.

Mr Brown, a former Chancellor of the Exchequer, has called for a transfer of £4 billion in VAT revenues to the Scottish Parliament but many of his own Labour colleagues deem that unworkable and view it as simply an annoying intervention. It is unlikely to happen.

Where he is on the same page as the majority of his colleagues is in his opposition to the devolution of all income tax to Scotland.

While they might not have cast it as a "Tory trap", many Scottish parliamentarians at Holyrood and Westminster believe Scottish MPs would eventually be excluded from voting on budget decisions on income tax, which could be detrimental to the material interests of Scotland.

Regardless of the outcome of the Smith Commission, the voting rights of Scottish MPs in the House of Commons will remain a running sore and it needs to be fixed. But the Smith Commission should get on with doing what is right and what the electorate expected. Other constitutional questions should be left for another day.