Green Party of Canada Leader Elizabeth May has pleaded guilty to violating a court injunction after she was arrested at a Kinder Morgan property in Burnaby, B.C.

May was arrested with several others on March 23, including NDP MP Kennedy Stewart and filmmaker Zack Embree, when she joined protesters to rally against the expansion of the Trans Mountain pipeline system.

On Monday, B.C. Supreme Court Justice Kenneth Affleck ordered May to pay a $1,500 fine, triple the $500 penalty imposed on Stewart, who also pleaded guilty, earlier in May.

Elizabeth May speaks to reporters outside the B.C. Supreme Court on May 28, 2018. Facebook video by Dylan Sunshine Waisman

Justice Affleck says Elizabeth May 'exploited' her role as MP

The hefty fine also was higher than the $500 penalty requested jointly by both the Crown and defence attorneys, Greg DelBigio and Casey Leggett, in the case.

Affleck acknowledged his decision to reject that request was "unusual," but he said that May had a responsibility as an MP and as a lawyer to obey the injunction.

"We can easily look to other places in the world to see where the rule of law has never existed or has been lost, and the dire consequences in the daily news," Affleck told the court. "The law applies to everyone. No one can pick and choose the law because they believe they have a higher obligation."

He also said that May had "exploited her role as member of Parliament and party leader" while encouraging others to defy the injunction.

"With privilege comes responsibility and Ms. May had the responsibility to obey this injunction and persuade others to do so," Affleck said. "Her punishment for criminal contempt must be greater than that of persons who do not hold positions of authority and influence. I cannot accept a fine of $500 as recommended by the Crown and defence. It is unusual for judges to depart from joint submissions, but in this case I conclude that it is appropriate to do so."

Speaking to reporters later, May said that she respected the rule of law, but was defending her own principles.

"Sometimes laws are broken in order to gain greater societal change," May said, following her plea.

Crown suggests jail time for Kinder Morgan opponents

Earlier in the day, Crown prosecutor Trevor Shaw opened the hearing by proposing an escalating series of penalties for those who defy the injunction, including jail time.

He proposed that anyone who pleaded guilty now would pay a $500 fine or do 25 hours of community service. But after this week, he proposed tripling all fines to $1,500 with 75 hours of community service. This would eventually increase to a fine of $4,500 or 225 hours of community service.

After June 25, Shaw proposed that people who choose to go to trial could face up to 14 days in jail if they are found guilty.

The latest court developments come with only days remaining before Kinder Morgan's self-imposed May 31 deadline to save the project. The Texas energy company has said it would walk away from the Trans Mountain expansion if it is not able to resolve uncertainty, before the deadline, caused by opposition in B.C. and a threat by the provincial government to use all tools available to protect its coasts, rivers and lakes from spills.

May blamed Kinder Morgan for triggering the conflict.

"They set this up," May said. "They kidnapped their own project. As kidnappers, they've taken their own project hostage. They've made the Government of Canada jump through hoops. They forced something I never thought I'd see: the finance minister (Bill Morneau) saying we're prepared to underwrite a project that takes fossil fuels to other countries — violating the Liberal Party election platform."

Protesters stage an 'oil spill' before the hearing

Before Monday’s hearing, Kinder Morgan opponents staged a demonstration to voice their opposition to efforts by Prime Minister Justin Trudeau and Alberta Premier Rachel Notley to push through the pipeline expansion.

Three of them, dressed as Trudeau, Notley and company founder Richard Kinder, dumped a mixture of molasses from a steel barrel onto the sidewalk outside the courthouse to simulate an oil spill. The three activists then proceeded to throw fake money on the spill before using some Q-Tips and paper towels to clean it up.

The organizers said they staged this event to remind arrestees and their supporters of the risks the pipeline poses, and why they're in court.

Kinder Morgan opponents stage a fake oil spill outside the B.C. Supreme Court on May 28, 2018. Facebook video by Dylan Sunshine Waisman

Editor's note: This article was updated at 4:35 p.m. ET with additional background details and quotes. It was updated again at 7 p.m. ET with additional details.