The Unite union official at the centre of the Grangemouth dispute has resigned from his job at the plant.
Stevie Deans was investigated by the company following his involvement in the row over the selection of a Labour candidate in the Falkirk constituency.
Grangemouth owner Ineos said in a statement: "The company has conducted a thorough investigation into Mr Deans' activities over the last 18 months and made Mr Deans aware of these findings last week.
"Mr Deans requested an additional five days prior to the final disciplinary hearing to allow him time to provide any further relevant information.
"The company was due to meet with Mr Deans again tomorrow but has now received his resignation."
Ineos threatened to close the petrochemical side of the business but changed its mind after the Unite union accepted changes to pay, pensions and other terms and conditions.
Unite said it will not comment until officials meet union members at Grangemouth.