Cameron takes on the Andy Murray question

He has overcome two hurdles - a temperament that makes Gordon Brown look giddily cheerful and the everlasting cliché of the "dour Scot" to have us all rooting for him this afternoon.

Lurking beyond the excitement is the "Andy Murray question": when you watch him battling away on centre court do you instinctively consider him Scottish first and British second or the other way round?

This conundrum, like the West Lothian one on voting rights, is the offspring of the devolution settlement of 1997.

The late Labour devolutionist Donald Dewar has been proved wrong in one aspect of his aspiration: granting more power to Scotland over its own affairs has not quelled the appetite for independence or drawn a line under the related questions of sovereignty and accountability south of the border.

Indeed, it has also thrown up a sense of resentment abut Scotland's beneficial public-spending settlement and brought fresh salience to Tam Dalyell's hoary puzzle: why should Scottish MPs vote on English business when English MPs have no such say over arrangements like education, healthcare and prisons beyond Berwick-upon-Tweed?

This asymmetry might well have simply remained a finals question for politics students - "Oh God I hope the West Lothian Question doesn't come up, I've forgotten the answer" - were it not for the present dominance of public services in the political argument.

The sight of the Scots receiving free tuition, exemption from prescription charges and other boons denied the English is a crucible of bad feeling. "How can they afford it?" cries the enraged English taxpayer. Well they can't, actually: the money is running out, the public services are unreformed and it comes home to roost in bad health outcomes in Scotland, a declining education system and stubbornly low life expectancy in poor urban areas.

In the short term, though, the comparison festers. Meanwhile, the Conservatives are mesmerised by the thought of giving Labour an English rout. Just as ardently, Scottish Nationalists are waiting for a Tory government to do just that in order to harden up pro-independence feeling on their turf. Labour is ground remorselessly between the two hostile plates.

A by-election in Glasgow East with a majority of 13,000 is now seen as a trial for Gordon Brown. Until recently, it would have been his party's birthright.

For the Tories, Ken Clarke's "Democracy Taskforce" paves the way to a manifesto commitment to address the "English question", in order to redress the lopsided constitutional effect of the Scottish parliament.

David Cameron is signalling that he likes the idea - and already reaping criticism for pandering to narrow English nationalism. That strikes me as wide of the mark. In fact, the Tory leader is going for the middle ground, having taken a look at a beefier English sovereignty and recoiled, as a good former student of politics should, from the unintended consequences.

So the genie of an English parliament is stuffed firmly back into the bottle, deemed too likely to guarantee an immediate lurch for independence and a rival to Westminster. Mr Cameron does not want to go down in history as the man who revived the Tories and broke the Union.

Instead comes the plan that Scottish MPs would be able to vote on early readings of a bill but not at the later refining, committee stage. Neither would they be able to overturn an amendment agreed by English MPs. This is at the mild end of the "English laws" crusade.

It makes sense because it recognises that resentments do exist and that the constitution does not adequately absorb them at the moment.

It also waters down earlier proposals from Sir Malcolm Rifkind and Kenneth Baker, who wanted an English Grand Committee - which sounds faintly Masonic - to handle all stages of laws affecting only England.

I happened to share a platform with Sir Malcolm when he was at his most orotund on this matter. It struck me as barking. For a start it would debar any future Scottish prime minister or cabinet minister from voting on laws affecting England.

A responsible Tory PM would not get away with forging a settlement predicated on eternal Conservative rule. Placing blanket restrictions on who may carry out what role at Westminster is asking for a big bust-up about the Union.

A legitimate objection is that the Tories today are playing with the tinderbox without accepting that there might be fire. "We must answer the West Lothian question," announces its statement this week, as if this were a pressing emergency. To which one answer would be: "Must we?"

But Mr Cameron can see an open goal at a time when Labour is struggling to hold onto its English support. His problem will lie not in gaining support for the idea south of the border but in explaining how on earth it will be implemented.

The call for English votes on English laws is as hard to define in practice as Mr Brown's mythical "British jobs for British workers", which is why, despite being mooted from the late-19th century Home Rule debates onwards, it hasn't been adopted.

Scottish (and Welsh) MPs will claim that so-called "English laws" have a knock-on effect on them and ask a Tory government to prove otherwise. The job of parliament's speaker will become overtly political in that he or she would have to rule which bills or parts of bills different groups of MPs are to vote on. MPs will sporadically disagree and seize up the very voting system the solution is intended to make fairer.

Alas for the Government, it cannot easily make hay by criticising the Tory plan. The PM has somehow ended up as popular neither in Scotland nor in England, and he badly needs a lifeline in both places

Scottish Labour's clan feuding has reached epic proportions. Wendy Alexander, who resigned as leader last week, had already fallen out irretrievably with Mr Brown over her call for a referendum on independence.

I have some sympathy with her view that it is better to call the Nationalists' bluff sooner rather than later. Mr Brown, however, is exercising due self-preservation in not approving a referendum on anything right now, having seen the state of his poll figures.

As much as all this sounds like the selfabsorbed entanglements of the Westminster village, it is about our understanding of how we want Britain to work and what we feel about it.

We may have to accept that devolution has changed the relationship between England and Scotland for good and prepare to absorb the consequences.

To that extent, Mr Cameron is asking the right question, however messy his answer. However he fares on court, the Andy Murray question isn't going to go away.