HOUSTON -- Some Houston businesses trying to block the city’s efforts to regulate air pollution are getting help from an unlikely ally—the Texas agency that monitors air quality.

The Texas Commission for Environmental Quality contends the city ordinance requiring businesses to pay registration fees for various sources of air pollution is inconsistent with state law.

The agency’s general counsel, Les Trobman, made the assertion in an April 24 letter to the Harris County District Court judge weighing a business coalition’s lawsuit against the city over the ordinance.

The position caught city leaders off guard, who said Friday they’ve met several times with agency officials in recent months without mention of the ordinance in dispute.

“It’s quite strange that the state’s pollution control agency would meddle in the city’s lawsuit on behalf of the polluters,” Kathy Patrick, an attorney representing the city, said in Saturday editions of the Houston Chronicle. “It’s a complete puzzlement.”

In a statement, the TCEQ said the letter was sent to the court to provide information that already had been relayed to the city.

The business coalition, funded by some of Houston’s heavy industries, filed the lawsuit against the city in February, arguing that businesses could face penalties for things considered lawful by the state.

Under the ordinance, businesses are required to pay registration fees, based on the number and type of pollution sources on each site. Fees range from $100 for a dry cleaning plant with fewer than six employees to $12,000 for plants emitting more than 10 tons annually of airborne contaminants.

Houston uses the fees to monitor air quality and to investigate complaints of violations of the Texas Clean Air Act. Those found breaking the state law can be fined by the city, according to its ordinance.