Activists intent on bringing chaos to a G8 summit of environment ministers have been warned that 1,000 police will form a "ring of steel" around the talks.

Officers from 23 UK forces will be on duty in Derby and surrounding villages as ministers from the eight leading industrial nations gather for the two-day conference.

The policing operation, which will cost over A£1 million, is the biggest Derbyshire Police project since the miners' strike of the mid-80s.

Environment Secretary and Derby South MP Margaret Beckett and International Development Secretary Hilary Benn are hosting the event at Breadsall Priory.

The impact of extreme weather on African communities and the environmental threats caused by illegal logging will be discussed at the summit, which is part of the UK's presidency of the G8 group of industrialised countries.

Ministers will ask how rich, industrialised nations can reduce their consumption of illegally-logged timber, and improve monitoring procedures.

Sources say Britain could help ensure supplies come from properly-certified sources by encouraging public authorities to use only legal timber for building works.

Protesters hope to use the meeting as a warm-up for demonstrations at July's main G8 summit in Scotland.

Home Secretary Charles Clarke has sanctioned council requests for bans on marches and demonstrations in the area.

Police have been granted powers to prevent trespassers from entering an exclusion zone surrounding the venue, and will deploy specialist "spotters" to identify known trouble-makers.