The current Scottish political scene is dominated by Alex Salmond, the nationalist first minister, and his two principal adversaries, Gordon Brown, the UK prime minister, and Wendy Alexander, Labour leader in the Scottish parliament. During the past fortnight the three have engaged in a frenetic and increasingly absurd dance round a relatively obscure issue, the timing of a Scottish referendum on independence.

Mr Salmond, as usual, was surefooted. Mr Brown and Ms Alexander were inept and leaden in their inability to co-ordinate their steps. The coming man in UK politics, David Cameron, the Conservative leader, could sit this one out. But the problem for Mr Cameron is that he may not be able to sideline himself from such Caledonian fandangos for much longer.

If we look ahead two or three years, the stakes will be much higher for those who wish to preserve the constitutional integrity of the UK. Independence referendums might be the least of it. Here is a perfectly feasible scenario: Mr Cameron wins the next UK general election and in doing so achieves domination in England but still lacks any significant representation in Scotland. This outcome would highlight the fact that the Tories are no longer a credible UK party in that they have such a small base in Scotland. Labour, for all its travails, is unlikely to lose representation in England to the extent that the Tories already have in Scotland.

Mr Cameron, if he really cares about the future of the Union, will have to move very adeptly. There will be pressure on him to address the grotesque over-representation of Scotland at Westminster: 59 MPs, none of whom can represent their constituents in the many matters over which the Scottish parliament has sway. (For this reason Professor Anthony King has trenchantly suggested that these Scottish MPs are in effect “eunuchs”.) People often forget that Westminster MPs such as Mr Brown, Alistair Darling and Des Browne, who represent Scottish seats, cannot deal with their constituents’ problems in all the many devolved matters.

This is a nonsense, but it is not yet an explosive issue. In England, the Scots are currently perceived to be unfairly benefiting from the Labour-driven devolution settlement, but the discontent is simmering gently rather than boiling over.

Scots, on the other hand, are rarely slow to find something to be disgruntled about and would soon be aggressively aggrieved if an English Tory prime minister, with derisory representation in Scotland, engaged in any policies that did not resonate well north of the border. To reduce the number of Scottish Westminster constituencies (many of them traditional Labour strongholds) could be construed as challenging the Scots to contend for independence. Yet it would be a reasonable and responsible initiative.

Think back to Margaret Thatcher. She won three UK general elections. She maintained her electoral popularity in England (in terms of votes cast) over this period – something Tony Blair did not manage to do. At the same time, she utterly alienated Scotland, so that by the time she was removed from office by her own MPs in 1990, the Tories had just 10 Scottish MPs at Westminster, compared with 22 when she first swept to power.

This suggests two things; first, that the Tories’ serious and continuing unpopularity in Scotland is rooted in the Thatcher years, not the later devolution settlement that Mr Blair ushered in immediately after his 1997 victory. Polling evidence endorses this interpretation. During the Thatcher premiership Scottish enthusiasm for the Union diminished significantly.

Second, it means that Mr Cameron will have a significant Scottish problem. So far he has hardly indicated how he will address it.

The dilemma is simple. If he deals with the crux, that Scotland is over-represented at Westminster, then he risks wrath in Scotland and will be accused of behaving as the leader of an English rather than a UK party. If he does nothing he will be practising appeasement. Baroness Thatcher steered well clear of any constitutional change in Scotland, and little good it did her north of the border.

Mr Cameron will need to gird for hard action. My view is that he should be bold and confront the problem of Scottish over-representation at Westminster head on. It would be the statesmanlike course of action; it would also enhance the Tories’ position at Westminster. But it might make Scotland even more turbulent.

The writer was editor of The Herald, Glasgow, 1997-2000