Five learned societies may go to court over a demand to pay rent on government-owned offices that have been rent-free for more than 125 years.
The societies are seeking legal advice on the strength of the informal agreement struck with the government in 1874 for free occupancy of Burlington House, on Piccadilly, London. This has allowed them to use the grade II listed building provided they maintain its internal fabric.
The issue was first raised in 1994 when the then Department of the Environment said the societies should pay commercial rents. Now the government wants to register the societies as "tenants at will", which would allow it to charge rent and give them two years' notice to quit the buildings.
A spokesman for the Royal Society of Chemistry, the Geological Society, the Royal Astronomical Society, the Linnean Society and the Society of Antiquaries said: "If the status is going to change, we need to know so we can plan for the future. It's like having the sword of Damocles held over the societies' heads."
Last week, the societies told the House of Commons science and technology select committee that inhabiting rent-free accommodation did not constitute core government funding and did not compromise their independence.
They said they would not be able to remain in central London if they had to pay commercial rates of rent, estimating that Burlington House could cost them £500,000 per year.
The only documentation in existence setting out the lease arrangement is from letters and oral undertakings, some documented in Hansard. The societies have been advised that this can be construed as a contract allowing them to remain as long as they like.