A Sussex woman campaigning against GM crops is facing a possible jail sentence for destroying part of a farm trial while under a court injunction.

Rowan Tilly, 43, and accomplice Kathryn Tulip, 42, defied the civil injunction to rip up maize at a farmscale trial site at Rosemaund Research Centre in Preston Wynne, Herefordshire.

It was the second time they had hit the trial site in a week. Last Monday they were part of a group of five campaigners who targeted the base to destroy 40 per cent of maize suspected of genetic modification.

Yesterday the pair were defiant and said they would keep protesting in the face of the threat of imprisonment.

Miss Tilly, of Brighton, said the fear of GM crops pollinating was far greater than her fear of being behind bars.

Miss Tilly and Miss Tulip, of Oxford, were joined by Mike Davies, 39, of Coventry.

They decided to return to the site after trial managers Aventis claimed they had destroyed controlled crops instead of GM maize.

The trio spent more than four hours on Saturday destroying up to 60 per cent of a different part of the field to ensure they had ripped up GM crops.

The two women were placed under an injunction by Aventis two years ago for taking part in a rally against GM crops in Norfolk.

The penalty for breaking the injunction could be imprisonment.