A national official of a leading trade union was arrested today at the site of a new bio-ethanol plant which has been at the centre of an increasingly bitter row over jobs.
Sources said GMB official Phil Whitehurst was arrested by Humberside Police under Section 14 of the Public Order Act outside the plant at Saltend, near Hull.
Mr Whitehurst is due to attend peace talks today in the latest attempt to resolve the dispute, which flared months ago after hundreds of workers were laid off, sparking unofficial industrial action.
A series of demonstrations have been held outside the site and there was a warning yesterday that thousands of workers at power station and oil refinery sites across the UK could be involved in a national day of action.
A GMB spokesman said: "Our legal officers have been examining the police use of Section 14 and the union plans to issue a legal challenge."
Electricians and scaffolders yesterday refused to cross picket lines at the new plant, being built by Vivergo for BP.
It is believed that union shop stewards from across the engineering construction industry will meet next week to discuss organising a national day of protest unless the row is resolved.
The action would involve thousands of workers from power station and oil refinery sites across the country and would be the worst outbreak of industrial unrest since a row over foreign labour at the Lindsey oil refinery in North Lincolnshire two years ago.
Vivergo said yesterday that it had made an offer of £3,500 to hundreds of workers affected by the termination of a contract with their former employer, Redhall Engineering.
"We have continually stressed to the unions that, when new contractors are in place, any new employment opportunities will be advertised so that former Redhall workers can apply for the jobs.
"The new contractors will be impacted by ongoing protest activity, which is why we are trying to resolve the situation quickly for the benefit of all concerned.
"The priority remains to get construction at our site back on track - opening up any new employment opportunities and to ensure that the 500 wider contracted workers can continue in employment," said a spokesman.
A Humberside police spokesman said a 56-year-old man had been arrested outside the plant under Section 14 of the Public Order Act and taken to a police station in Hull.
Maria Ludkin, the GMB's legal officer, said: "GMB members who have been locked out of the site since March have been engaged in lawful, legal protest against BP and the main contractors.
"Every attempt by the union to get BP to reopen the site to allow our members to complete this engineering project has been met with a blank refusal to even acknowledge that these workers have rights which are being trampled upon.
"GMB will challenge any charge in the courts and is preparing a complaint to the Police Complaints Authority, in relation to the provocative and overbearing policing of this dispute."