Care home residents are "effectively barred" from voting in person in the elections by guidance that requires them to self-isolate for 14 days after leaving the home, a care group has said.
Guidance from the Department of Health and Social Care (DHSC) states this is to ensure that residents who may become unknowingly infected do not then pass coronavirus to other residents and staff.
But it states: "We recognise that in practice, this is likely to mean that many residents will not wish to make a visit out of the home." The National Care Forum said it is a "national scandal" that residents' access to the voting booth on May 6 will be restricted.
This group of people will be feeling that their voices and opinions are "less valid and less valuable than the rest of the population" said the membership body, which represents not-for-profit providers.
Chief executive Vic Rayner said: "The whole experience of voting for the majority of people living in care homes will have been in person, often for many years at the same polling station, going through the motions in a way that is both familiar and a connection to wider society. Getting the vote is a rite of passage.
"Losing the right to vote in person is a national scandal."
Care home residents will be able to register for a postal vote or for a proxy to vote on their behalf.
But Ms Rayner said this should be a choice, and not because other opportunities have been removed.
She said: "As soon as it became apparent that everyone would not be able to share full access to the voting options, then the elections should have been paused, or we should have found a way where the opportunities for all to vote were equalised.
She added that it "should not be acceptable" that residents cannot vote in their local polling station without having to isolate for 14 days, when the rest of the population is out going to the pub, shopping and even socialising in gardens.
A previous version of the DHSC guidance, introduced on March 8, limited visits out of care homes to residents of working age.
It was updated last week, dropping restrictions preventing people over the age of 65 from taking trips outside the home.
It followed a legal challenge by the group John's Campaign, which argued that the Government was acting unlawfully by imposing a blanket ban regardless of the health of the individual.
The group said at the time that it wants to see the 14-day self-isolation requirement amended.