HALIFAX -- You don't need to be obese to stand up for the rights of obese people, the Federal Court of Appeal has ruled in a case over "discriminatory" airline seating policies.

The appeal court ordered the Canadian Transportation Agency to take another look at a passenger rights advocate's complaint over Delta Air Lines' policy of bumping obese travellers or making them buy two seats.

The agency had dismissed Gabor Lukacs' complaint because it found he didn't have standing since he was not obese and wasn't directly affected by the practice.

"I'm very pleased with this decision," Lukacs said Thursday before heading into a classroom at Dalhousie University, where he teaches mathematics.

"It recognizes the basic moral principle that you are allowed to stand up for the rights of others. It is a simple question of solidarity."

In its 16-page decision Wednesday, the federal appeal court unanimously agreed that the agency erred in law. The three-member panel found that the fact that someone may not be directly affected by a practice should not prevent them from filing a complaint.

"If the objective is to ensure that air carriers provide their services free from unreasonable or unduly discriminatory practices, one should not have to wait until having been subjected to such practices before being allowed to file a complaint," the panel wrote.

"There is no sound reason to limit standing...to those with a direct, personal interest in the matter."

The agency said in an email statement it is reviewing the decision and could not comment.

Lukacs said that while the decision deals with one particular issue, it could open the door to more people being able to file complaints with the agency, a quasi-judicial tribunal mandated to provide consumer protection for air passengers and ensure accessible transportation.

"From now on the Canadian Transportation Agency cannot toss out a complaint on the grounds of standing," said Lukacs, who was awarded $750 to be paid by the agency. "It will have to look at whether the complaint has some merit."

The complaint stemmed from a 2014 email from a Delta customer care agent to a passenger who felt he was "cramped" on a flight by a large passenger. The passenger notified Delta, which provided him with an explanation of the airlines guidelines.

In apologizing to the man, Delta said it sometimes asks large passengers to move to an area of the plane where there is more room, "purchase additional seats," or take another flight.

In a statement Thursday, Delta called the appeal court ruling "a procedural matter," and said it didn't change the airline's position.

"Delta will continue to fight Mr. Lukacs' claims vigorously," Delta spokeswoman Kate Modolo said.

At the time he filed the appeal in April, Lukacs argued that dismissing his complaint simply because the issue didn't affect him personally was akin to disregarding someone's concerns over contaminated food just because they weren't made sick by it.

As well, he said he has a demonstrated expertise in the area of passenger issues, having filed more than two dozen successful complaints with the agency and, as a result, bringing about improvements to the industry.