Some argued there should be a Devo Max question on the ballot paper for the independence referendum.

The Edinburgh agreement negotiated between Alex Salmond and David Cameron ruled that out.

But the question of what greater powers might be on offer to Scotland in the event of a No vote remains a live one and a significant one for voters.

Both Ruth Davidson of the Scottish Conservatives and Scottish Labour Leader Johann Lamont have set up commissions to look at greater devolution of powers to Scotland.

The suggestion from both has been that if Scots vote No to independence, the country could still get more powers over its own affairs in matters such as tax and welfare policy.

The accusation from the Yes camp has been that Better Together and the pro-Union parties have fought a negative campaign and have failed to make a positive case for the Union.

Those arguing for independence have also claimed promises from other party leaders of further powers for Scotland down the line cannot be trusted. So talks at a high level between the pro-Union parties aimed at setting out a clear offer of further devolution are a very welcome development.

The intention, according to Liberal Democrat peer Jeremy Purvis, is to present a united front and strong alternative to the Scottish people.

Politically, this is an adept move. The cynical view is that the intention is to prevent the Yes campaign from dictating perceptions of the debate, so that it is not a simple choice between change and the status quo.

When an agreed stance is revealed, perhaps in the final months before the independence poll, voters will be given the chance to choose instead between independence and a refreshed version of the Union.

That is the spin. But this isn't just politics, it is good for voters. In making this vital decision about Scotland's future, voters want to know not only the consequences of independence, but the consequences of rejecting it.

These could be major in their own right. One likely outcome of the push for a joint position from the unionist parties is a promise to hold a new Constitutional Convention in Scotland.

This might inevitably lead to a UK constitutional convention as well. If, as sources suggest, Labour and Liberal Democrat leaders Nick Clegg and Ed Miliband are now supportive of the idea of revisiting the UK's constitutional future, the longer-term outcome could be a uniquely British form of federalism.

It is clear that Scotland needs greater powers, whether or not independence is the route. This is particularly true of social security and economic policy where needs and public attitudes are often very different from those driving decisions at Westminster.

This week we are promised enlightenment as the Scottish Government publishes its referendum white paper. This debate has already seen more than enough squabbling and this has alienated many. An equally coherent offering from the opponents of independence will be to the advantage of all concerned.