The government will be taken to court over the crisis in care homes, ITV News understands.
Campaigners will continue legal action, after the government refused to change the rules around visiting.
Families say guidelines violate human rights because they have led to blanket bans of visits.
The action will be launched by John's Campaign, as ITV News Political Correspondent Paul Brand has previously reported.
Solicitors for the campaign wrote to the Health Secretary Matt Hancock, but the government replied on Wednesday, declining to change the rules after initially saying it was too busy.
Campaigners want the guidelines on visits to be more flexible, taking into account a resident's personal circumstances.
Thousands of residents haven't seen a single family member since March.
But the government remains very concerned about the risk of infection, with cases rising in care homes.
John's Campaign told ITV News the government is "prioritising infection control while under-estimating or even disregarding the risks posed by social isolation, loneliness and depression. It fails to assess what risks (usually minimal) are actually posed by family members."
There is no simple answer to any of this.
The view of campaigners is that focus on Covid is coming at the cost of all other considerations.
But the government is determined to protect care homes after the first wave of the virus led to 15,000 deaths in England alone.
Do they risk visits just as cases are rising?