The referendum on independence for Scotland is more complicated than most.

Opinion is divided not only between those who want outright independence and those who want to remain in the United Kingdom but with a third group which favours increased powers for the Scottish Parliament short of independence.

That makes a referendum with a single question requiring a yes or no to independence unsatisfactory to those who want to vote for a further transfer of powers from Westminster. The possibility of a second question offering that option would satisfy this apparently growing constituency but is politically fraught.

The official stance of all parties is to favour a single yes/no question. This has the advantage of producing a clear result on a simple majority. However, as the campaign for "devo-max" led by Future of Scotland, a coalition of voluntary organisations and trade unions, has gathered support, it seems a single-question referendum will fail to reflect the view of the Scottish people.

As The Herald's political editor Magnus Gardham reveals today, this is exercising political minds at the highest level. The involvement of the First Minister's office in sending the Future of Scotland group information useful to their campaign for a second question reinforces the view that Alex Salmond now favours a two-question poll.

However, the information that 62% of Unite trade union members favour a second question on devo-max also poses problems for the Labour Party, which supports a single question although significant numbers of Labour voters would like two questions. Last week Henry McLeish, the former Labour First Minister, warned his party that, unless they gave serious consideration to a second question on further powers, they risked increasing the vote for independence.

This in turn, leaves Mr Salmond in a quandary of whether to gamble on that being the outcome of a single question or going for two questions which would result in increased powers.

It is now crystal clear that the Scottish people want to know what they are voting for and will not be bought off with promises of constitutional jam tomorrow.