Electoral reform campaigners have warned of a ‘crisis of legitimacy’ in local elections as research reveals the first-past-the-post system leads to widespread disproportionality.

In an analysis of the May local elections in England, the Electoral Reform Society (ERS) found that in 115 of the 248 councils holding elections, a party won more than 50% of the seats with less than 50% of the vote.

In the most extreme case, the ERS found that the Conservative Party took all of the seats up for election on Havant Council with just 43.9% of the vote.

This compares poorly with Scotland which has been using the Single Transferable Vote (STV) electoral system since 2004. In the Scottish local elections in 2017, no council saw a party get more than half the seats with less than half the first preference votes.

The ERS’ research also discovered that in 17 English councils this May, the party with the largest number of votes did not secure the most seats, creating ‘wrong winner’ results.

‘This research shows how our broken electoral system is distorting local election results,’ said Jess Garland, director of policy and research at the ERS.

‘First Past the Post is delivering skewed results in over a hundred councils across the country meaning many voters’ voices are unheard.

‘England continues to rely on this disproportionate system for local elections, where only the votes for the top candidate to ‘get over the line’ secure representation – all others are ignored. Spread out over thousands of contests, this can lead to some parties being drastically over- or under-represented.’

Dr Garland compared the English voting system to the STV system used in Scotland.

‘Since 2004, voters rank candidates by preference and “surplus” votes are redistributed according to voters’ choices. Most advanced democracies use proportional systems where seats more closely reflect parties’ share of the vote,’ she said.

‘It’s time we ended the broken first-past-the-post system in England – a system that continues to warp our politics. A more proportional system would help open local democracy and make sure all voters’ voices are heard.’