The phrase “standing up for Scotland” has, for the past decade or so, been owned by the Scottish National Party.

It’s a nationalist rallying cry, indicating to voters that the SNP are defending and advancing whatever it deems to be the Scottish national interest.

But the phrase has had previous owners. Way back, it was the Liberals and Labour Party who said they “stood up for Scotland”, while I recently completed a PhD looking at how the Unionists (or Conservatives) claimed the same mantle between the 1930s and 1950s.

Looked at from this angle, it becomes clear that the dynamic of Scottish politics is both ideological and nationalist. At various points, every party in Scotland has harnessed nationalism to win or maintain power; in the 1980s and ‘90s it was Scottish Labour, now it’s the SNP.

This has its corollary in other parts of the UK. The reason Labour remains in power in Wales is because Carwyn Jones has most plausibly presented himself as “standing up for Wales” (especially since Brexit), although “standing up for Northern Ireland” is necessarily more complicated.

In England, too, it’s becoming more important for politicians to demonstrate they’re “standing up” for the UK’s largest component part. Indeed, at a Labour conference fringe event this evening – “Will the Union survive Brexit?” – academics will present evidence that Jeremy Corbyn’s party is now most trusted by voters to represent English interests.

This is a marked departure from previous surveys which suggested dissatisfaction among English voters with Labour’s response to the “English Question”. Now, however, almost a third say it’s best placed to “stand up for England”, compared with a quarter identifying the Conservatives and just 9 per cent saying the busted flush that is UKIP.

Only last year, Nigel Farage was England’s custodian, while the year before it was the Conservatives, who successfully played the English card in that year’s general election, mobilising English sentiment with posters depicting either Alex Salmond or Nicola Sturgeon pulling Ed Miliband’s strings by holding the balance of power in a hung Parliament.

Awareness of this nationalist dimension to English politics also explains David Cameron’s speech in the wake of the 2014 independence referendum, when he signalled the introduction of “English Votes for English Laws”. But not only was that policy logistically and politically flawed, it’s also been a damp squib, with more than half English voters feeling the UK Government has failed to make significant progress in standing up for England.

So, what does this mean for Scottish and British politics? I reckon there’s both an opportunity and a danger, primarily for the Labour Party. As Professor Richard Wyn Jones of Cardiff University points out, the challenge is for Corbyn et al to capitalise on English voters’ trust and “craft a popular, sustainable solution…without losing its appeal across the UK as a whole”.

Given that both the Scottish and UK Labour Parties are increasingly federalist in their thinking, this ought to be relatively straightforward, although Corbyn, who as a left winger is suspicious of nationalist politicking, might not be best placed to deliver. There are also internal tensions – yesterday Greater Manchester Mayor Andy Burnham criticised Labour for being “too London-centric” in its approach.

And what complicates things further is Europe. Today, Scotland’s Brexit minister Mike Russell and Deputy First Minister John Swinney are in London for the latest round of talks with Theresa May’s deputy Damian Green. And Messrs Russell and Swinney are, naturally, “standing up for Scotland” by demanding a differentiated Brexit deal which the UK Government (and Labour) feels unable to endorse.

The Prime Minister, of course, has been attempting to present herself as standing up for Britain, an even more complicated task. In her Florence speech late last week, Mrs May attempted to square the circle, suggesting the European Union had never “felt” to Britons “like an integral part of our national story”. The “British electorate”, she added, had made its “choice”, “strengthening the role of the UK Parliament and the devolved Scottish Parliament, Welsh and Northern Ireland Assemblies in deciding our laws”.

There are several problems with that, not only the majority Remain votes in Scotland and Northern Ireland, but continued confusion over which powers – previously held in Brussels but implemented via Edinburgh, Cardiff and Belfast – will revert to the devolved institutions rather than Westminster. In Florence, Mrs May also ruled out UK membership of the European Economic Area (the Scottish Government’s preferred compromise) on grounds of sovereignty.

All this puts the Conservative Party’s 13 Scottish MPs in a bit of a bind, not least because they were presented post-election as constructively “standing up for Scotland” within the Union, rather than the obstructionist approach of the SNP. The DUP-Tory deal undermined that piece of spin, not least because Scottish Secretary David Mundell clumsily framed the whole thing in terms of the Barnett Formula, which was never going to apply.

So, unless there’s a non-Barnett tartan-wrapped goodie in the forthcoming UK Budget, then there’ll be precious little for the 13 to point to and say “here’s how we stood up for Scotland”. One of the new intake, Angus MP Kirstene Hair, has even admitted to not voting in last year’s EU referendum, saying she’d taken the decision to leave it “to everyone else”.

One UK Government minister protests that they haven’t had enough time, and that the “real question” is who’s actually “listening to the people of Scotland”, particularly farmers, universities and bankers the Scottish Government feels unable to deal with as they’re “minded to endorse UK frameworks”. Time, I suppose, will tell.

But Unionists used to be better at this sort of soft-nationalist statecraft, Labour and the Conservatives presenting themselves as standing up for Scotland and Wales while also defending the British national interest. Brexit makes that much harder, but without that sort of approach, the UK will most likely face another existential threat.