A group of climate change activists who plotted to shut down the UK's second largest power station have been invited to launch appeals against their convictions.
The 20 protesters received letters from the Director Of Public Prosecutions after a review of the activities of an undercover police officer surrounding planned demonstrations at Ratcliffe-on-Soar power station.
The group, convicted of aggravated trespass, were among more than 100 people arrested when police raided the Iona School in Sneinton, Nottingham, on the morning of Easter Monday, April 13, last year.
Keir Starmer QC said he was inviting the protesters to appeal against the convictions after a review by Clare Montgomery QC into the "non-disclosure of material" relating to the activities of the undercover officer.
The DPP said: "Ms Montgomery has now completed her review and, having carefully considered her conclusions, I believe that the safety of the convictions should be considered by the Court of Appeal as soon as possible.
"The prosecution cannot lodge an appeal to the Court of Appeal save in very limited circumstances, which are not met here, and in my letter I have invited the defence to lodge an appeal and to include the issue of non-disclosure of material relating to the activities of an undercover police officer in any grounds of appeal.
"I have also indicated that the CPS will assist in any steps necessary to expedite the appeal."
The safety of the convictions is a matter that can only be dealt with by the Court of Appeal, he said.
"I am satisfied that, despite the ongoing reviews into what happened in this case, this is the only proper course of action. It would be wrong if, having reached this conclusion, I waited until the reviews were completed before contacting the defence about a possible appeal.
"As reviews into the handling of this case have yet to report, it would not be appropriate for me to comment further on any issues involving the undercover officer."
The protesters were convicted at Nottingham Crown Court on December 14 last year.
In February this year, the head of the Association of Chief Police Officers (Acpo) said undercover policing operations should have to be authorised in advance by a judge.
Sir Hugh Orde, Acpo president, said the change was needed to restore public confidence following concerns about the role played by ex-Metropolitan Police constable Mark Kennedy, who spent seven years posing as an environmental activist.
Mr Kennedy spent a reported seven years under cover posing as an environmental activist known as Mark "Flash" Stone.
Six protesters accused of planning to invade Ratcliffe-on-Soar claimed prosecutors dropped charges against them after Mr Kennedy offered to give evidence on their behalf.
The 20 convicted by a jury of conspiracy to commit aggravated trespass all escaped jail terms.
The protesters, who received a mixture of community orders and conditional discharges, were:
David Barkshire, 44, of Sheffield; Paul Kahawatte, 25, of Whitstable, Kent; Ben Julian, 34, of east London; Spencer Cooke, 42, of Belper; Martin Shaw, 46, of Oxford; Phillip Murray, 25, of Canterbury; Anna Rudd, 31, of Leeds; Adam Waymouth, 26, of Whiteparish, Salisbury; Bradley Day, 23, from Swansea; Chris Kitchen, 32, from Colchester, Essex; Daniel Glass, 27, from Glasgow; Emma Sheppard, 29, from Manchester; Jesse Harris, 24, from Leeds; Jonathan Leighton, 21, from Glasgow; Olaf Bayer, 35, from Southampton; Lisa Kamphausen, 26, from Southampton; Jacqueline Sheedy, 45, of Foulden Road, London; Clare Whitney, 25, from Cambridge; Sarah Shoraka, 33, of north London, and Ben Stewart, 36, also of north London.