I think we can safely say we've never seen an opinion poll quite like this before. I did wonder in my previous blogpost whether the first poll after the European elections would put the Brexit Party in an outright lead - that hasn't quite happened, but it's just as dramatic a story as that.
Britain-wide voting intentions for Westminster (YouGov):
Liberal Democrats 24% (+6)
Brexit Party 22% (+4)
Conservatives 19% (-5)
Labour 19% (-5)
Greens 8% (+2)
SNP / Plaid Cymru 6% (+1)
Change UK 1% (-1)
UKIP 1% (-1)
Scottish subsample: SNP 44%, Conservatives 19%, Labour 12%, Liberal Democrats 11%, Brexit Party 7%, Greens 6%, Change UK 1%, UKIP 1%
What remains to be seen is whether the Lib Dem and Brexit Party surges are the real deal, or whether they're Cleggasm-type effects that will ebb away once memories of the Euro election fade. But if by any chance things carry on like this, the SNP could be in a with a golden opportunity of cleaning up at the next general election, because for the first time ever they won't have to deal with the perception that people need to vote for a Labour government as the only alternative to the Tories. Instead, they'll quite reasonably be able to point out that a vote for the SNP is the only credible way in Scotland of helping to stop Farage.
The one possible fly in the ointment, as I suggested the other day, is that it looks likely that the next Lib Dem leader will be a Scot. But even if the Scottish Lib Dems do get some sort of Swinson boost, and even if they feed off the UK bandwagon effect, they can only realistically hope to win in a relatively small minority of constituencies. There are huge swathes of Scotland where the SNP are the only conceivable beneficiaries of a Tory and Labour collapse.