The Catalan election at the weekend has attracted a lot of interest here, and comparisons are being drawn left, right and centre. Peter Jones in the Scotsman finds it rather baffling that the centre-right independence party of Artur Mas lost vote share while independence-supporting parties overall boosted their position.

Jones suggests two main reasons for this apparently odd result, the first being the austerity imposed by Mas’s administration before the election, and the second being some kind of cultural argument that he either didn’t flesh out or I simply don’t understand. The idea that one of the reactions to austerity is a shift left makes sense, though.

And it’s true, the three other parties in the Catalan Parliament who now support some form of independence are all more radical than Mas: the Republican Left, narrowly now the largest opposition party with 21 seats; the ICV (the Greens’ sister party there, with a strong ecosocialist side) who went up to 13 seats, plus the Popular Unity Candidates, who won 3 seats.

By coincidence, the Radical Independence Convention met in Glasgow as Catalans voted. I couldn’t make it, unfortunately, but if you read the press, it sounded rather depressing. If you followed it on Twitter, however, it was buzzing with ideas and collaborations and points of contact, all united by two common themes. First, support for independence. Second, a desire for that independent Scotland not be a kind of timid low-tax tartan-austerity Westminster-remade-in-Edinburgh.

Instead, delegates wanted various more radical versions of independence, typically ones where control over the details of the constitution is vested in the people, where there’s room to build support for a Scottish republic with its own currency, a Scotland outside NATO, not beholden to the banks and the speculators, more equal, so on and so forth. It’s a desire which extends into the SNP too, despite the cautious approach the leadership seems determined to take, as illustrated not least by the close vote on NATO.

Again, by coincidence, the Scottish Greens picked their top candidate for the 2014 Euro election this weekend, choosing Edinburgh councillor Maggie Chapman from the party’s left. First elected in 2007, Maggie will be the Greens’ most experienced top candidate ever.

These three events look intertwined to me. The June 2014 Euro-election will come just four months before the independence referendum itself, and it would be a serious mistake to think the media won’t regard the it almost exclusively as a prelim for the October vote. Given that likely media narrative, let’s accept it, and confidently treat that vote as a test of views on the constitution.

If you want a more radical version of independence in October and after, voting Green will be the only plausible way to indicate that (apologies to friends in the SSP). If you want an independence referendum that isn’t just tied to the SNP’s agenda, either because you think that can’t win or because you’d prefer an open constitutional process, electing a Green MEP will be the only credible way to try and achieve it.

What’s more, to get a third SNP MEP elected in place of the Lib Dems takes three times as many votes on average, given the specific electoral system. In real life that varies quite widely. To take 2009 specifically, it would have taken 47,000 more Green votes nationwide to take that final place, but more than 60,000 extra SNP votes would have been needed to see the Nats get a third.

The risk of failure is substantial, too. Two pro-independence MEPs out of six, as now, and both from the same party: it’s quite a plausible outcome, and it would be seen as a massive dent in the Yes Scotland campaign. Electing Scotland’s first Green MEP, especially in a climate where this vote is seen as Scots giving their view on the constitution: that’d be a major prize for Yes.

Just as in Catalonia, that way the main party of independence might make no progress, but the cause of independence itself can be advanced and diversified at the same time. It’ll mean the Greens making an explicit pitch for the Radical Independence Convention vote in the runup to that June, and I hope that’s how the party chooses to take it. Cllr Chapman’s well placed to lead that argument.