GW Pharmaceuticals , the medicines from cannabis group, rose 13.5 per cent to 60p on further consideration of Thursday's report from the UK drug regulator on Sativex, its treatment for spasticity in people with multiple sclerosis.

Investec Securities said: "For the first time there is almost no ambiguity on what must be done to gain approval - and in our view what remains to be done [a Phase III clinical trial] is limited."