Nottinghamshire Police say a protest by 15 campaigners, staged inside two chimneys at West Burton power station near Retford, is costing £20,000 a day to police.
The campaigners say they plan to camp inside the chimneys for a full week and this morning have taken to flying kites and tweeting pictures.
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Breezy and rather cloudy this evening and overnight.
Mainly dry to start with some clear spells but remaining windy and mild.
Bright and blustery conditions with a few scattered showers.