Child Poverty Action Group could face industrial action by union members because of a dispute over contracts for new staff.
Negotiations are continuing between trustees of the anti-poverty pressure group and members of the Transport and General Workers' Union over the new deal, which threatens to withdraw some benefits that are enjoyed by existing staff.
One issue under dispute is a bid to abolish a three-month sabbatical earned after five years' service for new staff members.
There are around 20 Transport and General Workers' Union members at the Child Poverty Action Group out of a total staff of 29.
A spokeswoman for the union said: "There is deep unhappiness among staff over the new contracts and that they were introduced without consultation."
Two weeks ago, members of the Amicus union came within eight votes of sanctioning strike action at the RSPCA in a dispute over redundancies.