The key question in the Scottish region for the European elections is whether the Scottish National party can win a morale-boosting three seats out of the six up for grabs, only a week before the official campaign period for the independence referendum starts.

The SNP, which comfortably won the most votes in the 2009 European elections with nearly 30% against 21% for Labour, currently holds two seats, with Labour also on two, and the Conservatives and Liberal Democrats on one apiece.

With their activists and supporters energised by the referendum campaign, opinion polls suggest the SNP may get an historically high vote of up to 37%, taking their third seat at the expense of the ailing Lib Dems.

Some pundits believe the SNP's actual performance may not hit that level, however, dashing their hopes of a third seat.

Those same polls put the Lib Dems at just 6 to 7% of the vote, trailing the UK Independence party which some polls put as high as 10%. Eyes will also be on Ukip's result: their chances of winning their first seat in Scotland are slim but the size of the vote – which hit a high of 6.7% in 2004, will be closely watched.

The SNP and pro-independence movement have repeatedly singled Ukip's rise in England as evidence that the UK is already splitting apart, with Scots far less sympathetic to that Euro-sceptic, anti-immigration agenda.

The early declarations from the 31 Scottish councils which are counting today suggest the turnout will likely be higher than the 28.5% achieved in 2009. That implies the referendum has boosted voter interest.

Edinburgh has seen a turnout of 41.6% - the highest of the 18 councils to declare a turnout so far, well up on its 35.5% turnout in 2009.

The official vote for Scotland will not be declared until Monday lunchtime, because the Western Isles will not count on a Sunday for religious reasons. But with a population of just 21,000 its vote is unlikely to significantly affect the overall result, so Sunday's voting figures are expected to be accurate.