New US president Barack Obama's Monday move to tighten vehicle emissions standards has drawn a mix of applause and criticism.

Pennsylvania state governor Edward Rendell hailed the decision. "After years of delay, this move is good news for those of us who are working to address climate change and declare our independence from foreign oil," he said in a statement.

Like 10 other states, Pennsylvania adopted California's stricter vehicle emission rules, but has not realised greenhouse gas reductions from the rules because California has not been permitted to enforce that portion of its clean vehicle programme.

Rendell repeatedly challenged the Bush administration's efforts to restrict or delay efforts by Pennsylvania and other states to improve air quality by limiting greenhouse gas emissions from vehicles.

Last January, Pennsylvania joined a multi-state lawsuit against the EPA challenging the federal agency's refusal to grant California a waiver to enforce its stronger greenhouse emission standards.

In testimony before the US senate, Rendell said the EPA "wrongfully and illegally" blocked state efforts to ensure cleaner air and water to protect public health and safety.

On the other hand, Obama's announcement drew criticism from auto industry allies in Washington who warned the policy change would compound the auto-industry crisis, according to Dow Jones Newswires.

Representative Mike Rogers, a Michigan Republican, said Obama's order all but ensures that one of the Detroit-based auto companies would be forced to seek bankruptcy protection without further federal aid.

"When you lay these heavy costs of burden when they're already weak in the knees, somebody's not going to survive," Rogers said in an interview with Dow Jones Newswires. "It's clear one of these will have to come beg for money."

Michigan Democrat senator Carl Levin said in a statement that he had been assured by the new EPA director and another administration official that the review of California's request wouldn't be conducted with a "foregone conclusion."

"I sure hope that is true, because a separate California standard will not only create the 'confusing and patchwork set of standards' that president Obama [on Monday] implied he wanted to avoid, but also, as the California standard is currently drafted, it is discriminatory against US-made vehicles of the same efficiency as the imports," Levin said in his statement.

Debbie Stabenow, a Michigan Democrat senator, noted that lawmakers passed legislation in 2007 calling for national environmental standards for cars.

"A strong, national standard is what the country needs, not a confusing patchwork of different state standards," Stabenow said in a statement cited by Dow Jones.

Dave McCurdy, CEO of the 11-member Alliance of Automobile Manufacturers, said in a statement: "The alliance supports a nationwide programme that bridges state and federal concerns and moves all stakeholders forward, and we are ready to work with the administration on developing a national approach."

"Today in the U.S. there are three voices on fuel economy/CO2 - NHTSA, EPA and California - and each has different standards, different structures and different timelines.

"Automakers seek a federal-state solution that provides us with compliance clarity and one national standard.

"The alliance also urges the Obama administration to issue fuel economy standards for MY2011, because automakers are working on their product plans now and need the certainty of final standards."

The National Automobile Dealers Association (NADA) urged the administration to closely examine how new rules would actually be implemented.

Its legislative affairs head, David Regan, said in a statement: "We welcome a close examination of the California Air Resources Board's (CARB) rule to regulate fuel economy in competition with the federal CAFE programme.

"With almost 1,000 auto dealerships closing last year at a cost of over 50,000 jobs, we are hopeful the President and the EPA administrator will realise that a single national fuel economy standard set by his administration is smarter than a patchwork of state regulations that further endanger the struggling auto industry.

"For example, apart from being completely contrary to the federal method of regulating fuel economy, CARB's regulation would create a 'cross-border' sales loophole that not only threatens the economic well-being of our dealers who sell in [the 12] 'California' states, it also allows CARB's rule to be easily and legally evaded, resulting in no environmental benefit. 

"Congress needs to hold hearings to ascertain how many jobs are going to be lost because of this loophole, so the true cost of CARB's rule can be known before a decision is made."

NADA last week released a comprehensive report, entitled Patchwork Proven', on the numerous unintended consequences that it said would cause economic harm and provide little or no environmental benefit over standards by allowing individual states to regulate fuel economy.

"The analysis clearly shows that the exemptions, loopholes, and unforeseen outcomes will come at a high price and not reduce greenhouse gases (GHGs) nationally," NADA said.