A "landmark" victory has been claimed for postal workers who objected to moving from weekly to monthly pay.
The Communication Workers Union won a test case at an employment tribunal on behalf of two workers, after complaining that the Post Office was intending to switch employees on to a new salary schedule, without their consent.
CWU assistant secretary Andy Furey said: "When the Post Office first made their announcement, the union responded that if the employer wanted to make such a change then it needed to obtain agreement and to pay compensation to employees who were prepared to make that accommodation.
"Instead, the Post Office just went ahead and tried to impose the change. We offered to take the issue to Acas for resolution, but the Post Office dismissed the offer out of hand."
The union said it was prepared to discuss any proposal to move from weekly to monthly pay for members in the Crown Offices and supply chain, but on the condition that they are properly compensated for the disruption that the change will cause.
A Post Office spokesman said: "We continue to reflect on the judgment and are considering our next steps.
"The vast majority of people working for Post Office have been paid on a monthly basis for many years. This change was required to ensure all employees are served by a robust and efficient payroll system which also supports meeting our pension automatic enrolment obligations which were introduced in May 2017.
"Post Office went to great lengths to ensure that no employee was adversely affected financially, through providing an interest free salary advance of four weeks' pay with a variety of repayment options, which included repayment of the loan on the employee leaving the business, payment of any bank charges or penalties incurred and the provision of financial planning advice.
"It was accepted that the two claimants have not financially lost out because of the change from weekly to monthly pay."