The nation’s 45,000 airport-security screeners will be allowed to vote on joining a union to negotiate on shift assignments, job transfers and awards.

Screeners will vote on joining the American Federation of Government Employees, the National Treasury Employees Union or no union, TSA said today in a statement

Screeners won’t be able to bargain over security-related issues such as pay, job qualifications and discipline standards, according to the statement.

“The safety of the traveling public is our top priority and we will not negotiate on security,” TSA Administrator John Pistole said in the statement. “Morale and employee engagement cannot be separated from achieving superior security.”

An election is scheduled to start March 9 and end April 9 and will be overseen by the Federal Labor Relations Authority, which oversees relations between the government and its workers.

Security officers will remain barred from striking or participating in work slowdowns if they vote to join a union, according to the TSA statement.