The Green party MP Caroline Lucas is to be charged over her part in an anti-fracking demonstration in Sussex.
Lucas was arrested last month at Balcombe where campaigners have been protesting about oil drilling in the village amid fears that it could lead to fracking in the area.
The Crown Prosecution Service said Lucas would be charged with breaching a police order on public assemblies and wilful obstruction of the highway.
Nigel Pilkington, a senior lawyer with the CPS, said: "After careful consideration we have concluded that there is sufficient evidence and that it is in the public interest to prosecute Ms Lucas.
"Sussex police has therefore been authorised to charge one count of breach of a section 14 order contrary to section 14 of the Public Order Act 1986 and one count of wilful obstruction of the highway contrary to section 137 of the Highways Act 1980. Both offences are alleged to have taken place on 19 August 2013."
Lucas will appear at Crawley magistrates court on 9 October.
Protests have been staged in the village of Balcombe since Cuadrilla began testing oil-drilling in the area. The energy firm received planning permission three years ago to drill a 915-metre (3,000 ft) vertical well and a 760-metre horizontal bore south of the village.
Lucas confirmed she had been charged and said she remained "deeply concerned" about the impact of fracking.
She said: "Sussex police have today confirmed I am being charged with two offences arising out of my arrest in Balcombe on 19 August.
"One of the offences is for obstructing the highway. The other is for failing to comply with a police condition to move to a specified protest area.
"I firmly believe in the right to peaceful protest and remain deeply concerned about the impact of fracking on climate change and the wider environment.
"I have been advised by my lawyer to make no further comment at this stage."