Phil Whitehurst, from the GMB, was arrested by police a fortnight ago for an alleged breach of the Public Order Act at a £200m biofuels site at Saltend, near Hull, where workers have been demonstrating for the past two months.
About 400 workers were laid off in March after Redhall Engineering’s contract for the mechanical and piping work was terminated.
The move comes after the majority of workers indicated they were prepared to accept an offer of £4,000 from Vivergo, the owner of the plant. However a small percentage are still fighting to be given their jobs back under the same terms and conditions when a new contractor is appointed.
The GMB said Mr Whitehurst would be pleading not guilty. They have instructed prominent human rights firm Bindmans to represent him.
Vivergo said they hoped the acceptance of the offer signalled the end of the dispute and the protests at Saltend. They are looking to place new contracts “imminently” to get the work finished.