Synagogue buildings given heritage status face increased costs that could run into thousands of pounds after the government decided to cut a grant that refunded VAT.
The cut, which will start in January, is part of the government's overall drive to tackle the economic deficit.
Currently synagogues, along with all other listed places of worship, can claim a grant equal to the VAT paid on certain specified works, including architects' professional fees. Now they cannot claim for those fees as well as work on items such as clocks, pews, bells and organs.
There are 37 listed synagogue buildings, according to a report compiled for English Heritage, which said it "regretted" the government's decision.
The news has been greeted with dismay at the Grade One-listed Old Hebrew Congregation, in Liverpool.
Trustee Julian Rosenthal said: "We are two-thirds of the way through major repairs to the building, costing many thousands of pounds, that do include architects' fees.
"We have to spend £150,000 in the next financial year to make the building watertight and we would pay VAT on that, so we would lose several thousands there as well. We have an agreement for further funding from English Heritage but now that is looking seriously in doubt."
At another Grade One-listed building, New West End Synagogue in St Petersburgh Place, central London, financial representative Harry Sieratzki said: "We have carried out very extensive repairs to the fabric of the building with a new roof and guttering that has cost £200,000-plus, including the VAT.
"It is a complete blow because we have had this work done and we have an obligation to pay. How can we make calculations if the government suddenly makes changes for the current financial year?
But Tourism and Heritage Minister John Penrose said: "Everyone is being asked to make cuts so I'm afraid we cannot exclude this scheme, however much I would like to."