ST. PAUL — Plans to adopt California vehicle emission standards in Minnesota hit a bump in the road Friday, April 3.

The state Pollution Control Agency had aimed to publish an official notice of its intent to adopt the Clean Cars Minnesota program this month, opening a new public comment period. But it announced Friday that the outbreak of the coronavirus here and the stay-at-home order accompanying it will push back the publication date, at least for now.

"As part of its reassessment, the MPCA has determined that timeline is no longer appropriate and is delaying publication of the rule temporarily," reads an agency announcement.

The announcement comes days after the U.S. Department of Environmental Protection announced it would effectively weaken federal emission guidelines established under President Barack Obama's administration. Gone will be the federal mandate for car manufacturers to improve fuel efficiency and emissions by 5% each year, replaced with one requiring only 1.5% improvement instead.

Proposed in late 2019, Minnesota's Clean Car program is intended to circumvent such a rollback. If adopted, it would require manufacturers to deliver cars for sale here that meet stricter emission guidelines first established in California.

Automakers would have to deliver a set number of low-emission and electric vehicles for sale in Minnesota under the state rule as well.

Despite the publication delay, the MPCA said Friday that it still plans to complete the approval process for the rule before the end of 2020. Even if that happens, the rule would not take effect until the start of 2023.

Friday's announcement came as another hiccup for state regulators, whose timetables for other measures continue to be disrupted by the virus. Earlier this month, the MPCA announced it would cancel public meetings on the controversial Line 3 oil pipeline replacement project to prevent possible cases of COVID-19, the respiratory illness caused by the coronavirus, from spreading in large-group setting.

The agency has since moved to hold public meetings on that project via the web, the first of which was held Thursday, April 2.

It said Friday that its priority for the Clean Cars rule was "ensuring that the public has opportunity to participate in the rule-making process," and that it will "continue to monitor this situation."

Environmental groups and electric vehicle maker Tesla have praised the proposal for its potential to cut pollution.. Minnesota car business officials, by contrast, worry it could burden them with expensive and possibly unpopular products, not to mention disrupt their relationships with out-of-state dealers.

State Republican lawmakers had earlier sought to block the rule change with a bill that challenges the MPCA's authority to implement it. The decision to tighten emission standards, they said, should be the Minnesota Legislature's to make.

But that bill's future is uncertain in a capitol that itself has been knocked silly by the pandemic. It has yet to pass out of committee in either chamber.

In a statement sent late Friday, state Rep. Dan Fabian, R-Roseau, who chairs the House Environment and Natural Resources Division, said the delay was appropriate given the disruption caused by the pandemic and the "fact that this rule will add thousands of dollars to the cost of buying a car here in Minnesota."

"Minnesotans are already facing significant financial challenges, and we should put a pause on any new costly new government regulations until the crisis is behind us and our economy has recovered," Fabian said.

Supporters and critics of the clean car rules have long debated their effects on new car prices. One commonly cited EPA report states that they could add about $800 in upfront costs.

The Minnesota Automobile Dealers Association estimates the rule could add up to $2,500. An MPCA cost analysis is still forthcoming, though agency officials and the EPA have said cleaner cars have performed better and thus yield savings in the long run.

If and when Minnesota adopts the rule, it would be the eleventh state to do so. The federal government allows states to either follow its own emission guidelines or California's.