An MP is leading calls to make it the law for care homes to allow visits from "essential care givers".
Guidelines introduced in July even during coronavirus outbreaks.
A Merseyside-based Rights for Residents group said not all homes were following the advice and during outbreaks some residents "are still dying alone".
Labour MP for Liverpool Walton, Dan Carden, said the "vital" visits should be "enshrined in law".
He has tabled amendments to the forthcoming Health and Care Bill to guarantee families have the right to visit loved ones in care homes.
"I have heard from families whose relatives have told them they would rather die than carry on existing in isolation," Mr Carden said.
"The emotional impact of being separated from a loved one, who may be in the last stages of their life, is absolutely heart-breaking."
Diane Mayhew, co-founder of Rights for Residents, told she was "absolutely delighted" when the government updated the guidelines.
However, she said many care providers were "refusing" to follow it, with some people "completely cut out" of their loved one's care.
Ms Mayhew said some care homes were shutting down during Covid-19 outbreaks, so "there are still people dying alone", and while the guidance is advisory and not mandatory it would continue.
She said she was an essential care giver to her partner's mother before her death in August and it "really helped" the carers.
Ms Mayhew said along with her partner, Jenny Morrison, they would help feed and entertain her mother as well do her nails and "all the things that carers just simply don't have time to do".
"That's why the essential visitor was brought about as well trying to support people with their mental health and wellbeing, but unfortunately that has not happened across the board," she said.
She said "it's not just the residents suffering" and it could be "soul-destroying" for relatives and loved ones.
A Department of Health and Social Care spokesman said it was "doing everything we can to support care providers to facilitate visits safely".
He said this included "ensuring all residents can nominate an essential care giver, removing limits on visitors and reducing the period of time visit restrictions apply following an outbreak".
"Our message is clear - all care home residents should be supported to get the care and companionship they need from visitors as this is essential to their health and wellbeing," he said.