The European elections should never have taken place – but now that they are it is no surprise they are all about Brexit.

Voters across the UK opted to quit the European Union almost three years ago, despite almost two thirds of Scots backing Remain.

Unsurprisingly then the SNP, and First Minister Nicola Sturgeon, are urging Scots to send a message to Theresa May that “Scotland is for Europe” in the ballot.

Two of the six Scottish MEPs who were elected five years ago came from the SNP, with another two from Labour and one each from the Conservatives and Ukip.

The SNP’s Alyn Smith, who has spoken out strongly against Brexit in the European Parliament, is hoping to be returned there after the votes are counted on Sunday.

But with three parties in Scotland campaigning on an anti-Brexit platform – the Greens and the Liberal Democrats as well as the SNP – Ms Sturgeon has insisted it is “vital that the pro Europe vote does not fragment”.

Tweeting before polling opened she said: “The independent analysis is clear – if you want to secure a majority of pro Europe MEPs, vote for the strongest Remain supporting party in your area. In Scotland, that is @theSNP.”

But the Greens, whose campaign slogan has been Choose Hope Over Hate, are hoping anti-Brexit sentiment could see their lead candidate, co-convenor Maggie Chapman elected.

Support for the Liberal Democrats in the South has been boosted by the party’s strong pro-EU message.

And in Scotland the lead candidate for the anti-Brexit group  Change UK, David Macdonald  has already urged voters to back the Liberal Democrats in a bid to keep Britain in the European Union.

Ending his candidacy he said: “I have come to the point where I have realised I must do what is best for the future of this country before anything else.”

With Labour leader Jeremy Corbyn having come under fire from within his own party for failing to take a strong stance on Brexit, lead candidate David Martin has been stressing his pro-European credentials.

Mr Martin, who was first elected to the European Parliament in 1984, is the UK’s longest serving MEP.

As well as being a supporter of a second European referendum, he has been urging Scots to back a “progressive Europe”.

Theresa May’s failure to deliver Brexit has seen support for the Conservatives slump across the UK.

And in Scotland the party is at risk of losing the European seat it won in 2014 to Nigel Farage’s Brexit Party.

But the party has been campaigning hard, arguing that the results of both the 2014 independence referendum – where Scotland voted to stay part of the UK – and the 2016 Brexit vote should be respected.

Lead candidate Baroness Nosheena Mobarik has called on Scots to back her party and use the election to send a message to Nicola Sturgeon that there should be “no more divisive referendums”.