Workers at the charity Child Poverty Action Group struck for the day on 17 September, in a strike for equality.
Management is bringing in new workers on terms worse than those current employees receive, with cuts in sick pay, compassionate leave and annual holidays.
The vote for strike action by Transport and General Workers Union members in a secret ballot was 98%. Twenty workers were on the picket line.
The voluntary sector while it includes many fluffy charities is notoriously stony-faced in its dealing with its own staff and their unions. But the strike is believed to have been the first among national charities.
RSPCA workers vote for action
The animal welfare charity the RSPCA plans to close its 10 regional call centres, sacking most of its workforce, and unite its operation in one call centre that will be put out to tender.
RSPCA workers, members of Amicus, have voted for industrial action short of strike action.