The former union branch president has been branded an "unfortunate pawn" in an internal plot to replace his regional secretary, a tribunal heard.

Andrew Irving, from Idle, took the GMB union to the tribunal claiming it had broken its own rules when it suspended him as branch president for Yorkshire and North Derbyshire.

He was suspended from the post in January last year by Jerry Nelson, 53, the regional secretary, and others, the tribunal was told.

The suspension came after Mr Irving, who is secretary of Ciba Speciality Chemicals, based in Lowmoor, Bradford, argued with union executive member Noreen Metcalf, at a Christmas dinner in 2005.

Mrs Metcalfe and Mr Irving later signed a statement saying they had resolved their differences amicably and Mr Irving was eventually reinstated, the tribunal in Leeds heard.

But he was immediately suspended again for acting in a way which might damage the union - by criticising Mr Nelson over the first suspension. Mr Irving complained to the Government's watchdog body for trade unions saying the union had broken its own rules. Susan Machin, for Mr Irving, said Mr Nelson and others had unfairly suspended her client and Mr Nelson had influenced the union's regional committee to back him in the decision.

The case centres on a letter and e-mail in 2005 from Mr Irving in which he alleged that Mr Nelson had asked Mrs Metcalf to continue her grievance against him.

Mr Nelson denied the charge and said that Mr Irving had been misled by "bad people" in the union who were seeking to undermine him.

He said: "Mr Irving is an unfortunate pawn and he has paid the ultimate sacrifice."

However, Miss Machin said that her client denied the allegations he was an unwitting member of a plot.

She said Mr Nelson had told an unofficial meeting of the regional committee before the disciplinary hearing to find against Mr Irving.

She said: "Do you, Mr Nelson, in any way accept that by discussing this matter in Andy Irving's absence, with a body of people who were ultimately going to hear the complaints against him, was unfair?" Mr Nelson replied: "no."