A hydraulically controlled pressure switch, comprising a spool having an elongate body with a first end and a second end, and an intermediate part between the two ends; a target movably connected to the second end of the spool by means of a spring; means for detecting movement of the target and providing an indication of pressure acting on the spool based on the movement of the target; whereby the spool is configured to cause movement of the target against the force of the spring based on the level of pressure acting against the first end, towards the spring, and also the level of pressure at the intermediate part between the two ends.