A public employer or its officers, or an agent of the public employer, may not spend public money, use public resources, or provide assistance to an individual or group for a negative campaign against efforts by employees of a public employer or an employee organization to: gain or retain collective bargaining rights; or certify an employee organization as an exclusive representative. Within 7 days after a valid election has been scheduled under Subtitle 4 of this title, the public employer shall allow public employees and employee organizations to access the employer’s property and facilities, including grounds, rooms, bulletin boards, interoffice mail, and other common areas for campaign activities for the election. The public employer may not: limit the amount of time a public employee has access to the public employer’s property and facilities during an election under this section; or alter or revise existing rules or regulations to unfairly limit or prohibit public employees or employee organizations from exercising their rights under this title. This subsection may not be construed to allow campaign activities to interfere with a public employer’s operations.