Almost 300 Calgarians have launched a legal challenge seeking to quash the city’s recently approved blanket rezoning program.

The Calgary Herald reported that 288 applicants are seeking a judicial review of the narrowly approved program that allows for higher-density residential projects.

Councillors voted 9-6 in favour of new regulations after they received about 40 amendments, the Herald reported. The 12 days of public submissions and three day of deliberation and discussion ranked as Calgary longest city council meeting, according to the Herald.

A weeks-long public hearing on the sweeping rezoning plan cost the city about $1.3 million, a report shows.

The approval has widespread implications for future rental-housing and condominium developments throughout the city. The court decision will likely affect numerous multi-family development projects as investors look to bring more capital off the sidelines due to the Bank of Canada’s recent decision to reduce its key overnight interest rate to 4.75% from 5%.

“We’d like to see the bylaw revisited and we’d like to see greater care taken in assessing whether a blanket, wholesale approach affecting 311,000 people is the best way to proceed,” Rusty Miller, one of the applicants of the court challenge, told the Herald.

If it is allowed to stand, the revised bylaw will enable the city to reorganize zones across the city.

As a result of council’s approval, the city will now permit the rezoning of all residential areas that had only allowed for single or semi-detached homes.

The Calgary Real Estate Board opposed the rezoning program.