Last month, the Administration delayed an EPA rule on ozone standards, part of a capitulation on regulatory rollbacks demanded by the business community in conjunction with Republicans. For years, the Administration told environmental groups not to sue to force new standards, because they were working on them. The environmental groups held their fire, suspended an active lawsuit from the Bush Administration, but then the White House caved.

Those same enviro groups are now taking the EPA to court.

Five health and environmental groups sued the Obama administration on Tuesday over its rejection of a proposed stricter new standard for ozone pollution, saying the decision was driven by politics and ignored public health concerns.

The groups said that President Obama’s refusal to adopt the new standard was illegal and left in place an inadequate air quality rule from the Bush administration. Near the end of his presidency, George W. Bush overruled the Environmental Protection Agency’s scientific advisory panel and set the permissible ozone exposure at 75 parts per billion.

The current E.P.A. administrator, Lisa P. Jackson, wanted to set the standard at 70 parts per billion, near the maximum level recommended by the advisory panel. But President Obama rejected that proposal on Sept. 2, saying that compliance would be too costly and create too much regulatory uncertainty for industry. He ordered the E.P.A. to conduct further scientific studies and come up with a new proposal in 2013.

EarthJustice, the American Lung Association, the Natural Resources Defense Council, the Appalachian Mountain Club and the Environmental Defense Fund are the groups involved in the lawsuit.

The Administration decided to postpone the standards, presumably to save corporations money, although on a cost-benefit analysis, the new ozone standards would have saved money overall because of public health benefits. Forcing capital upgrades at this time would also have a stimulative economic effect.

Tens of thousands of Americans are at risk of illness, asthma, lung disease and even death as a result of the lowered ozone standards. And prior court rulings, the groups say, force stronger regulation in this area. They will get their day in court to prove that.