Here's how to rescue Scots Tories, Mr Cameron

Dear Dave,

A thousand welcomes to Scotland, to you and your Tory shadow cabinet on today's flying visit north. I understand that you, Liam, George, Caroline and the others are here to apologise for "letting Scotland down", in particular by not offering Scots voters a convincing alternative to the present, unpopular Executive. As a result, the electors may have to plump for Wee Alex and the Nats, with dire consequences for the Union.

I know you get a lot of stick for "gesture" politics, but - extra carbon miles apart - I welcome the fact that you have dragooned your team into coming to Scotland for a day. It will impress on their collective mind the fact that the Conservative Party is an endangered species in these parts.

Back in 1955, your party polled 1,273,942 votes in Scotland at the Westminster general election. That was 50.1 per cent of the entire poll, and gave you 36 MPs. Labour grabbed 46.7 per cent of the votes and came second. The Liberals managed only one seat - the magnificent Joe Grimond - while the SNP polled a miserly 12,112 votes in total.

How are the mighty fallen. At the last Holyrood election in 2003, the Scottish Tory vote had dropped to 318,279 souls (in the constituency section). Even Tommy Sheridan's Trots managed 246,790 votes and the Greens got 132,138. So the combined vote of the parties to the left of Labour was actually a good 60,000 more than the Scottish Conservative vote. When you are out-polled by the Loony Left and the Greens, you have ceased to be an influence in real politics.

Before there can be a remedy, there has to be a diagnosis. The implosion of support for what we call the Scottish Conservatives can only be understood if we realise that this party did not actually exist prior to 1965. Before then, there was something called the Scottish Unionist Party (SUP), and it was a wholly autonomous organisation that thrived on its local roots.

The contemporary absence of a viable, Scottish right-of-centre political force is not the result of Maggie Thatcher or some inbuilt, collectivist conscience in the Scots middle class. Rather, it is because the London-based Conservatives of the Sixties were daft enough to crush the SUP and merge its rump into the English Tory organisation.

The old SUP grew out of a split in the UK Liberal Party at the end of the 19th century. Traditionally, the Liberals represented the industrial bourgeoisie and the urban proletariat against the Tory landed-aristocracy and City interests. Liberalism was a radical tradition deeply opposed to conservatism with either a large or small "c". North of the Border, these radical Liberals were the dominant political force - the Tories were a distinct minority.

But the Liberals split over support for Irish home rule, which was seen as a prelude to the break-up of the British Empire. In Scotland, the anti-Irish Home Rule Liberals carried away a third of traditional party support. As a result, there emerged a new party in Scotland, the Liberal Unionists. This lot absorbed the Scottish Tories in 1912, to emerge in due course as the dominant party north of the Border - the Scottish Unionist Party.

But the SUP remained at heart a radical, urban force, unlike the rural Tories down south. At a UK level, the party represented the direct interests of the Clydeside industrial bourgeoisie - meaning that the SUP championed Scottish economic needs, first and foremost. For instance, the massive expansion of the economic powers of the Scottish Office between the two world wars was at the behest of the SUP.

David, I'm sorry to teach my granny to suck eggs (as they say up here). But it is obvious that once the SUP ceased to be a Scottish political party in its own right, representing Scottish interests at a UK level, then the London-centric "Conservatives" - a political label not only alien but anathema even in the old SUP - would be rejected.

Can I put this in marketing terms? Why buy a powerful, profitable Scottish brand only to close it down and import an inferior copy? Of course you will lose customers hand over fist. And where did those customers go? It is no surprise that the rise of the SNP in the Sixties coincides with the death of the SUP.

If the rump of what are called the Scottish Conservatives wants to get back in the political game, it has only one choice - the kind of bold step that you, David, are taking with the Tories down south. Refreshing the right-of-centre (but still radical) brand means making the party wholly autonomous in Scotland and giving it a new name - shall we say, the Scottish Progressives? In other words, reversing the disastrous merger - forced takeover, actually - of 1965.

David: you can't fix this problem - you can only get out of the way. Do it quickly, and the Progressives could start their recovery in short order. Of course, I would expect that an influx of bright young professionals would sweep away the current, moribund leadership of the Scottish Conservatives. And the new Progressives would soon be demanding greater fiscal powers for Holyrood (in order to cut taxes).

This would not be the old SUP, but a modern reincarnation with 21st-century policy concerns. I can't even promise that Progressive MPs at Westminster would always vote with your English Conservatives, because they would represent Scottish interests.

But unless you want to be doomed to repeating today's visit every four years - an eternal pilgrimage to the festering corpse of Scottish Toryism - then be bloody, bold and resolute.