”Philistine” plans to save cash by closing three Bristol museums would unlikely deliver significant savings and must be dropped, Conservative councillors have claimed.

The council-run museums at Blaise Castle, the Georgian House and the Red Lodge museums could be shut completely, while the Archives Searchroom may have its opening hours cut back significantly. Last month council director Alex Hearn wrote to staff who work there warning of potential cutbacks.

He said councillors on the finance task group would be considering the proposals at a confidential meeting on December 16, which would look at ‘draft savings’ that could be made across Bristol City Council. But the suggestion of cuts to the city’s cultural offer has sparked outcry in some quarters – including among local Tories.

The council’s Conservative group leader Mark Weston said: “I was alarmed to hear of these philistine proposals which, many people will recall, have been aired before over ten years ago under the then elected Mayor George Ferguson in 2014. My group successfully rejected those moves then and wish to make it crystal clear to the current Green Party-led administration that we will resist any attempt to revive this plan.

“Aside from the destructive cultural and heritage implications from such cuts, it is far from clear how these could possibly deliver a real, tangible, saving. These are buildings are listed historical assets which could not be sold, and the council would still be responsible for maintaining them in good repair.

“Of course, closure would also deny us of the opportunity to explore potential revenue raising opportunities. Consequently, we have registered out implacable opposition to such ‘savings’ by tabling a formal resolution and questions on this pressing matter for the next meeting of the full council.”

In his letter to staff Mr Hearn insisted no decision had been made. “The council continues to face a significant financial challenge, with a projected budget gap for 2025/2026 of around £52 million, which is expected to rise to around £68 million over the next five years,” he told museum staff.

“Each service area has been asked to put forward draft savings proposals to help close this gap, including culture and creative industries. We have been modelling various options, and we are now at the point where a finance task group (made up of councillors) will be considering all the proposals.”

He continued: “At this stage a range of options are being considered to find savings, however the total savings required will depend on what is announced in the local financial settlement by the national government next week. While the amount we have to save will depend on this settlement, proposals being considered by the group include: the closure to the public of Blaise Museum, Georgian House and Red Lodge and a reduction in public opening hours of the Archives Searchroom.

“Although no final decisions are made on the council’s budget savings until full council in February, our current expectation, given the scale of the challenges, is that the above groups will be impacted in some way. Any proposed changes agreed will require public consultation of 12 weeks. If changes are approved after the consultation, any proposals that impact staff will be managed in line with the council’s Managing Change Policy, with support from HR.

“Please rest assured that the details of any specific proposals and timescales will be shared with you by myself or your managers,” he told museum staff, adding that decisions on exactly what will happen will be confirmed in the New Year, and the proposed savings will go to the council’s strategy and resources committee on February 3, and then to the full council meeting at the end of February.