SCOTS are being urged not to spoil their ballot papers accidentally at the local elections, with figures showing nearly 40,000 votes were discarded as being invalid in 2017.

Campaigners say the single transferable vote (STV) system can cause confusion for people more used to using a cross on their ballot paper to vote.

According to a recent study from the Electoral Reform Society, a total of 37,491 ballot papers were rejected at the count in the local elections of 2017, representing 1.95% of all votes cast.

The level of invalid votes also varied considerably from one local authority to another - in Glasgow, on average 3.4% of votes were rejected in each ward and around 3.0% in West Dunbartonshire. But that fell just 0.8% on Orkney and 1.1% on Shetland.

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The report notes that there is a “clear tendency for invalid votes to be higher in wards with more candidates”.

Willie Sullivan, director of Electoral Reform Society Scotland, said: “It’s to do with the fact that people are used to putting crosses in – I think most [ballot papers] are spoiled by putting two crosses in.

“The drawback of that is obviously far outweighed by the fact that we have a preference vote system and people can express how they really want to vote and not have to hold their nose or tactically vote etc.

“But no system is perfect – if you are using a system that requires crosses in one election and you have done for generations and then a system which requires numbers, then sometimes it is a bit confusing.”

He added: “If people spoil their ballot paper, that is up to them. But if they want to express a vote and they have put two crosses in, it won’t be counted."

The report notes the proportion of ballots rejected under STV in Scotland is more than under the previous first past the post system and greater than the figure in Northern Ireland, which is generally just over 1%.

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Sullivan said while the Electoral Commission and councils were generally doing a good job on raising awareness, there is still more to be done to make sure people know how to vote correctly under STV.

“Our message is it as easy as one, two, three,” he said. “It is getting people to realise you are just ranking your candidates – what one is your favourite, what one is your second and third favourite and so on.

“It is getting people to think in that way instead of the case where they vote Labour or SNP and there are two candidates, they just put crosses against the two.

“That is where it doesn’t get counted.”