The five mayoral candidates will no longer face one another in a single forum.
Charles Darwin University had advertised a debate, Vote 1 4 Alice, for March 20.
An invitation had been sent to Mayor Damien Ryan but his challengers didn't get an invite, according to one of them, Steve Brown
They meanwhile accepted the invitation of Mez Elliott who described herself as a part-time announcer and producer with Radio 8HA, to a meet-the-public occasion at the RSL on the same night.
Radio 8HA manager Roger Harris says Ms Elliott is not a producer with 8HA but "occasionally stands in on shifts when an announcer is away".
Hosted by Territory Today presenter Adrian Renzi, the RSL function will not be a debate but a question and answer session, also open to councillor candidates.
Mayor Ryan, however, will not be present, as once he became aware of the CDU cancellation, he accepted another invitation, addressing a visiting group.
A media release from CDU says: "The university accepts that no one’s interests are served in having two debates on the same night and that there is insufficient time to organise an alternative date.
"The university apologises to the mayoral candidates and to anyone else for any inconvenience."
UPDATE: Following the cancellation, Mayor Damien Ryan and Deputy Mayor Liz Martin will be hosting a " Meet the Candidates" night in Stuarts Bush Kitchen at the National Road Transport Hall of Fame on Thursday, March 22 from 6pm to 9pm.
Alderman Martin says this is not an Alice Springs Town Council initiative.
"We have invited all mayoral and councillor candidates to participate with equal opportunity and have had a good response to date. This is a casual evening that will allow members of the public, particularly those from various associations and industry groups who have already issued questionaires, to chat in an informal setting one on one with candidates to find out where they stand on issues that are important to them."
The evening will include a free sausage sizzle and transport can be arranged for those that dont have it by calling Ald Martin on 0429 201 549.