A controversial power company could begin drilling for oil in West Sussex as early as next month.
Cuadrilla has announced plans to dig a fracking exploration well near the Balcombe aqueduct this summer.
One campaigner said protesters were likely to try and disrupt the work “by any means possible”.
Fracking involves blasting water and sand at high pressure deep underground to cause mini-explosions which release shale gas.
Moves by the same company to exploit the unconventional fuel in Lancashire were put on hold after hydraulic fracturing caused two small earthquakes in 2011.
However Cuadrilla, has assured Balcombe Parish Council that it will not be using fracking at this stage.
Instead, the company plans to drill and take samples of the underground rock in a vertical well 3,000 feet deep.
If oil or gas is discovered, it will only be allowed to flow “for a short time”, the company said.
The work is expected to take no longer than four months, with planning permission set to expire in September.