The Canadian Association of University Teachers is threatening censure at King's University College in in London.

That could mean instructors wouldn't fill vacant positions at King's and guest lecturers or large symposiums wouldn't attend King's.

The controversy started when part-time instructor Ken Luckhardt wrote a letter to Kings administration after his retirment.

The letter got him banned from King's.

In an e-mail to CTV News from his new home in Georgia, Luckhardt says his intention was to express concerns about the King's social justice program.

The e-mail states "I feared the KUC administration was intent on drastically undermining the program and its Director."

Although CTV News has not seen the letter, there were other elements in it that concerned King's administration.

"There was an external investigator brought in and the conclusions were such that we upheld our policies," says Dr. David Sylvester, King's principal.

Sylvester wouldn't discuss the details of the case but a letter to the association calls the e-mails from Luckhardt disturbing and says they contained explicit personal and professional criticism of two junior female faculty members.

The letter to CAUT - the teachers' association - quotes the investigator using terms like vexatious, vitriolic, inappropriate, inflammatory, accusatory, objectionable and harassing.

But James Turk, executive director of the Canadian Association of University Teachers (CAUT) says a ban like this stifles the kind of discussion universities are founded on.

"To have that kind of spirited exchange defined as harassment when there's no evidence of any harassment in any just a precedent that would be very dangerous, not only for King's but for any other university in the country."

That's prompted the association to threaten censure.

"Censure has serious consequences but so does not protecting a safe environment for faculty, staff and students. I'm obligated by law to ensure that our policies are upheld and that our campus is discrimination and harassment free," says Sylvester.