Union members at the housing charity Shelter are being balloted on possible strike action over proposed changes to staff pay.
The union Unite said that it was asking its 330 members at the charity, which employs 1,300 people including those working in its shops, to vote on strike action over changes to terms that it said could lead to pay cuts of up to £5,000 a year for new advice and support workers and £3,000 for existing front-line staff.
The union said that in addition to cuts in salary for new starters, the charity was also seeking to implement a separate pay scale for existing front-line advice and support workers to that used for non-front-line staff.
Unite said the planned changes meant that some advice workers could earn up to £3,000 a year less than other Shelter employees on the same grade but in different roles.
Peter Storey, regional officer at Unite, said in a statement: "The proposed changes to pay are divisive and grossly unfair. Shelter’s front-line support and advice workers are the lifeblood of the charity, helping and supporting vulnerable people in difficult situations.
"It is disgraceful that the charity should seek to cut their pay by thousands of pounds while the pay of those with huge salaries at the top is protected. There appears to be one rule for one and one for another. It is not the way a progressive charity should behave.
"We would urge Shelter management to get back around the negotiating table to avoid damaging industrial action and reach an agreement that values its dedicated staff."
Campbell Robb, chief executive of Shelter, said in a statement that he was disappointed to hear of the ballot.
"At Shelter we aim to pay a broadly typical market salary across all roles and we benchmark salaries regularly to help us achieve this," he said. "In doing so we have found that we currently pay staff working in advice and support well above the salary for similar roles elsewhere, which with funding cuts and more competition for donors we cannot sustain.
"This leaves us with a simple but painful choice: keep the higher pay levels, cut our services and make some roles redundant, or maintain the number of people we help and reduce salaries for new staff. We always strive to be the best employer we can be, but in this instance we feel we have to put our ability to help those who need it first."
The ballot closes on Thursday.