Almost 8 million people who are eligible to vote in the European Elections are not registered with just days to go before the deadline, campaigners say.
Research commissioned by Best For Britain shows 7.9 million people who could vote in the poll aren't on the electoral roll in their area.
The analysis calculates the number of people eligible to vote for every region in the UK, based on the population aged 18 or over and nationality data.
This was compared against estimates of what proportion of the population are registered to vote in each region, based on the number of people on the electoral register and research from the Electoral Commission on the accuracy of the electoral register.
The analysis shows hundreds of thousands absent from voter rolls in each region.
Deadline to register to vote is TODAY - but Labour could make it automatic
Best for Britain supporter and Green MP Caroline Lucas said: "It's really concerning that huge swathes of people across the country who have the right to vote in the European elections this May, aren’t currently registered.
“This analysis shows nearly 8 million people could be at risk of losing the right to have their voice heard at such a crucial juncture for the country’s future, with young people, private renters and EU citizens some of the groups most at risk of missing out. That needs to change.
“Whether you voted leave or remain, your voice needs to be heard. Get out and get registered.”
