The federal government’s proposal to reduce smog will harm Pennsylvania manufacturers and the state’s broader economy, pro-business groups are warning in a new public-relations offensive against the upcoming regulations.

At least 33 of Pennsylvania’s 67 counties would be in violation of stricter emissions limits on smog-forming ozone, triggering mandatory curbs that could discourage factories from opening or expanding, stifle the natural gas industry, force delays in highway and bridge construction, and lead to expanded emissions testing for cars and trucks, according to a report by the Center for Regulatory Solutions.

The rule “could stall Pennsylvania’s recovery from the Great Recession and deny the commonwealth a long-awaited comeback in manufacturing jobs,” said the report, obtained by The Associated Press ahead of its release.

The Obama administration plans to finalize its ozone regulation by Oct. 1. The Environmental Protection Agency is proposing an emission limit of 65 to 70 parts per billion, saying a reduction in the existing standard of 75 parts per billion that’s been in place since 2008 will save lives and cut emergency-room visits.

The administration of Democratic Gov. Tom Wolf supports the stricter standard.