A Calgary couple who visited the Parliament buildings in Ottawa says a security guard told them they wouldn’t be allowed to go on a tour unless they changed their shirts that displayed support for the oil and gas industry.

Chris Wollin and his fiancé were wearing a black t-shirts that read, “I (LOVE) (CANADIAN) OIL AND GAS.”

“The security officer mentioned that if we were to come back with our "I love Canadian oil and gas" shirts on, that we wouldn’t be allowed to do the tour because you’re not allowed to wear any shirts that are too political,” Wollin told CTV News Calgary.

According to the Parliament of Canada's website, "participating in any form of demonstration inside the buildings is prohibited, including wearing items or clothing with visible political messages."

The shirt is designed by Canada Action, a non-profit organization that advocates for the advancement the oil and gas industry.

It’s the second time in two weeks that that Calgary visitors to Parliament Hill were asked to remove the shirts.

William Lacey, chief financial officer of Steelhead Petroleum Ltd., was wearing the oil and gas t-shirt  when he toured the Senate over the September long weekend.

He said he was swiftly taken aside by security and told to either wear the shirt inside-out or leave.

“The security guard looked at me and said: ‘Excuse me sir, I'm going to have to ask you to remove that shirt.’ And I looked and him and I said: ‘Excuse me?’ And he said: ‘Yes, you're going to have to remove that shirt because some people may view that as being offensive,’” Lacey recalled.

Guillaume Vandal with the Parliamentary Protective Service later apologized for the incident.

"Personnel misinterpreted a message on the visitor's article of clothing,” he wrote in an email. “The staff involved will be receiving operational guidance and training with respect to visitors to the Hill.”

Wollin feels both incidents highlight a disconnect.

“I think if my shirt had have said, 'I love the auto industry,' or 'I love the forestry industry' or whatever, it wouldn’t have been an issue,” said Wollin.

"So I’m not sure why there’s any sort of prejudice towards the energy sector. I think we should all be proud of it."