Prison officers in Guernsey say they are growing increasingly frustrated after waiting nearly two years for a pay increase.
The Transport and General Workers' Union thinks it is inevitable there will be some form of industrial action.
It says action can only be avoided if the Civil Service Board (CSB) honours an agreement to ensure local staff are given equal pay and conditions to their UK counterparts.
But CSB president Andrew Sauvarin said increased pay had already been awarded to the prison officers.
He said the Board and the union agreed to pay prison staff the same as their UK counterparts at an industrial tribunal on 12 December 2002.
He insisted that had been honoured and a pay increase was awarded to workers on 1 April this year.
Deputy Sauvarin said the Board had investigated the allegations from the TGWU and found them to be "without substance".