Caerphilly County Borough Council’s offices in Pontllanfraith could be closed as part of a bid to save £29m over the next three years.
Pontllanfraith House is home to around 400 staff who offer services including planning, housing and public protection.
Council officers claim its closure would save £736,000 a year and say they could sell the building for housing development, raising up to £2.5m.
At a meeting of the Policy and Resources Scrutiny Committee on December 8, councillors supported the draft budget proposal to close the offices.
Pontllanfraith Labour Councillors Mike Adams, Colin Gordon and Gez Kirby have spoken out against the recommendation.
Cllr Kirby said: “I spoke against the proposed closure of Ty Pontllanfraith at the committee meeting.
“We all recognise our council’s need to make savings because of the Tory Westminster Government’s cuts. But people in Pontllanfraith and across Islwyn value access to council services at Pontllanfraith House.
“I hope Islwyn residents will have their say about this plan in response to our council’s public consultation on budget proposals, before a final decision is made.”
However, some councillors believe selling buildings is a better way to save money than cutting services.
Plaid Cymru group leader Colin Mann said: “As a member of the Policy and Resources Scrutiny Committee, I supported the recommendation. But I understand concerns about the loss of offices in the Islwyn area, although the council does offer other services in the area such as the Blackwood Customer Service Centre.
“In the current financial climate if we can manage with fewer buildings then it means fewer savings in frontline services have to be made.”
Should the offices close, services and workers would be moved to Dyffryn House in Ystrad Mynach and Penallta House in Tredomen.
A Caerphilly County Borough Council spokesperson said: “This is one of a range of savings proposals put forward for consideration as the council looks to make financial savings of close to £40 million over the next three years. These proposals are currently subject to a period of consultation, and residents can have their say on these by completing a survey which can be found on the council’s website or in the December edition of Newsline, which goes to every home in Caerphilly County Borough.
“Council will then consider and approve the final savings proposals at a meeting of full council in February.”
A further consultation with employees and trade unions will take place if the plan is approved.