27. The pensionable salary of an employee who is released with pay to hold pensionable employment under this plan with an association representing the management personnel or for union activities is the salary paid to the employee by an employer and the salary, if any, paid to the employee by a body designated in Schedule III or, as the case may be, by a body designated in Schedule II.1 of the Act respecting the Government and Public Employees Retirement Plan (chapter R-10). The body concerned must pay its employer’s contributory amount and deduct the contributions from the pensionable salary it pays to such an employee.