One of the unnoticed areas of cross-party co-operation at Westminster is over the parliamentary timetable and big football matches. Crucial votes rarely, if ever, coincide with Champions League ties, and still greater care is taken over the World Cup. For the duration of England’s opening game in Group G, parliament was given over to a debate about the impact of Brexit on the devolution settlement, a subject that exercises the SNP but has little purchase outside the nationalist parties. That allowed many other MPs to cluster en masse around parliament’s televisions to watch Gareth Southgate’s men overcome Tunisia, thanks to a late goal from Harry Kane.

The score was level for a while, and after a promising attack in the 80th minute petered out, James Frith, the Labour MP for Bury North, jokingly suggested switching over to the SNP’s debate. “At least England’s winning that one,” quipped Kevin Brennan, the Labour MP for Cardiff West.

But is it? The SNP has been in office for more than 11 years in Scotland, a period after which most governments would expect to be getting a little mouldy. The Scottish economy only narrowly avoided recession in the opening quarter of 2017. The Conservatives – now the main opposition party at Holyrood – are led by the most popular politician in Scotland. And the SNP will be seeking a fourth term in office in 2021, a formidable task for any party. Yet poll after poll puts the SNP on or above 40 per cent, and few seriously expect Nicola Sturgeon’s party to be defeated at the next election.

The Conservatives in Scotland face a similar headache to that experienced by Labour in England. Under Ruth Davidson, they have successfully made themselves one end of a polarised politics: an explicitly and boldly unionist party. While Davidson likes to make great play of the SNP’s obsession with independence, she has brought up constitutional issues more frequently at First Minister’s Questions than any other topic. But the Scottish Tories have two problems. The first is that maximising their share of the unionist vote doesn’t get them anywhere near to having enough seats to take power at Holyrood. The second is that while Davidson has transformed the position of the Scottish Tories, she has not transformed their personnel. Although there are more of them (she inherited a parliamentary party of 15 MSPs and now leads one of 31) they are, as far as their politics and abilities go, still – in the words of one Scottish Lib Dem – “the same unlovely creatures” that made up much of the party at Holyrood before.

Davidson’s numerous cheerleaders often liken her to Tony Blair, and it’s true she has an easy charm that is reminiscent of Labour’s last election winner. But the more damning similarity is her failure to bring forward an equally impressive second generation. That failure will likely become more significant should, as many Conservatives hope, Davidson trades Holyrood for Westminster at the next general election.

As for Scottish Labour, in the past year it has changed its leader, its deputy leader, its communications director and its policy platform. The only thing that hasn’t changed is its poll position: it is third in all of them. The hope that the departure of Kezia Dugdale, an avowed critic of Jeremy Corbyn, and her replacement with Richard Leonard, a long-standing member of the Labour left, would change Scottish Labour’s position has proved entirely mistaken.

The problem is partly one of Leonard’s inheritance. Scottish Labour is now the third party, which means it simply gets squeezed out of the political conversation. That Labour has a less aggressive position on the constitutional question means it is better placed to gain tactical votes – anti-Tory or anti-SNP – which helps in a first-past-the-post election. But at Holyrood, where elections are decided by the additional member system, that ambiguity has fewer upsides and higher costs. Scots get two votes – one for their local constituency and another for the party list. Until the rise of the SNP, Labour never really needed to fight for both votes. As more than one Scottish veteran concedes, activists on the doorstep would often accept that voters might indulge themselves with a list vote for the Greens, while hammering home the importance of a Labour vote in the constituency.

All of which leaves Leonard largely ignored. Labour can credibly hope that, as with the Liberal Democrats in England, it will benefit from the increased exposure that the minor parties get during an election campaign – but it will have to navigate years of obscurity first, to the benefit of the SNP.

The Scottish nationalists’ main political project isn’t merely to maintain their dominant position within a devolved parliament; it’s to break the link between the governments in London and Edinburgh. On that measure, it is doing less well. Support for independence has increased among the 62 per cent of Scottish voters who opted to stay in the EU – but significantly, it has also declined among the 38 per cent who backed Leave. The net effect is stasis.

The other major drain on Sturgeon’s political capital is the Scottish government’s Growth Commission, a blueprint for the day after independence that is far more clear-eyed and honest about the trade-offs than anything the SNP produced during the 2014 referendum campaign. Senior SNP figures believe the Pollyannaish tone struck during the campaign inspired activists but turned off middle Scotland, and that they are well placed to avoid a repeat.

From its position in office – and with the bully pulpit that this affords – the SNP can set the terms of political debate and nudge discussions towards independence. Meanwhile, its unionist opponents look dangerously like that Tunisia side: sitting back, trying to defend an earlier goal, with no plan or prospect of scoring another.