The arguments for and against independence for Scotland have reached a crucial stage.

Both sides have asserted their belief that their relative positions – remaining a constituent part of the UK or becoming a separate nation – will be the most advantageous economically, socially, politically or strategically. But the absence of chapter and verse, facts and figures has reduced debate largely to claim and counter-claim.

For months, most opinion polls have found about one-third of voters undecided but the latest this week shows a move towards a No vote with the number still to make up their minds falling to 10%. Among them is Sir Tom Hunter, the entrepreneur who made £290 million from the sale of his Sports Division retail chain and, by any measure, a big beast in the business community. Both camps would be delighted to name him among their supporters but yesterday he allied himself with a significant strand of public opinion by saying he remained to be convinced by either side and criticising both campaigns. He challenged the Yes campaign to produce "hard facts to hard questions" and the Better Together campaign to produce more positive arguments and specify what additional powers would be transferred to Holyrood in the event of a No vote.

It is clear from all the public forums, including The Herald's Letters Pages, that this plea for clarity will resonate widely. Both sides have to produce convincing arguments but the onus is on the Yes campaign because, in the absence of a decisive case for change, the safer option of sticking with what you know becomes more attractive.

The increase in those saying they will vote No is an indication that this is already happening.

That is almost certainly due to confusion and increasing frustration over specific questions, such as whether an independent Scotland would retain the pound as currency; would remain a member of the EU without having to negotiate new terms of membership; and could be a member of Nato. In some cases there is, as yet, no definitive answer but the charge of failing to explore the most authoritative opinion and engage in detailed analysis can be levelled at both camps.

In addition to the questions surrounding international relations, there is increasing concern about economic issues at the UK, Scottish and personal levels.

Conflicting forecasts about future oil revenues are inevitable but the focus is increasingly on how they will add up and, more pertinently, be divided. Policy issues such as how to fund the sort of social welfare provision most Scots appear to want are the province of a future Scottish Parliament but the recent focus on how pension entitlement, whether through state, private or public sector schemes, would be funded following independence is evidence of a growing demand to address the consequences of independence at a personal as well as a political level.

With just under 500 days to go before Scots are required to make up their minds on the most significant vote in the country's history, Sir Tom is far from alone in calling for politicians to abandon the skirmishing and get into the substantive fight. His impatience for answers to so many crucial questions is shared by all who are anxious to weigh up the arguments and mark their ballot with confidence that they are making the right choice. They deserve a genuine, honest and informed debate.