A high-level group of experts has asked the Government to clarify its position on whether it intends to develop "incapacitating chemical agents" for a range of domestic uses that go beyond the limited use of chemical irritants such as CS gas for riot control.

The experts were commissioned by the Royal Society, the UK's national academy of sciences, to investigate new developments in neuroscience that could be of use to the military. They concluded that the Government may be preparing to exploit a loophole in the Chemical Weapons Convention allowing the use of incapacitating chemical agents for domestic law enforcement.

The 1993 convention bans the development, stockpiling and use of nerve agents and other toxic chemicals by the military but there is an exemption for certain chemical agents that could be used for "peaceful" domestic purposes such as policing and riot control.

The British Government has traditionally taken the view that only a relatively mild class of irritant chemical agents that affect the eyes and respiratory tissues, such as CS gas, are exempt from the treaty, and then only strictly for use in riot control.