The energy company Eon has passed another milestone in its efforts to build the UK's first coal-fired power station since the 1970s, but it could face a public inquiry following fierce criticism from environmental groups.

Eon plans to replace its ageing Kingsnorth coal-fired power station in Kent with a new, 1,600 MW plant on the same site. The German company says it intends to invest £1bn in the new facility, which could be generating electricity by 2012.