After months of fighting over spending, taxes and how to rein in the national debt, President Obama and congressional Republicans on Thursday turned the spotlight to the nation’s anemic economic growth and announced competing plans to reduce the cost of doing business for American companies.

The Obama administration said it would seek to scale back or eliminate hundreds of regulations affecting workplace safety, environmental protection, endangered species, hospitals and other subjects, saying the measures would save businesses billions of dollars a year.

“I hope that this process might inaugurate a broader, less polarized, more evidence-based conversation about how we might promote economic growth and job creation while protecting the health and safety of the American people,” Cass Sunstein, the administrator of the White House Office of Information and Regulatory Affairs, said in a speech Thursday.

House Republicans, meanwhile, offered a proposal that would lower the top tax rate on individual and corporate income to 25 percent from 35 percent. The plan would also strengthen patent protections against some lawsuits, require congressional approval of significant new regulations, increase domestic oil protection and promote the party’s effort to make large cuts in government spending.

“House Republicans know you can grow your way into economic prosperity. You can grow your way into jobs,” said Rep. Jeb Hensarling (R-Tex.).

The pair of initiatives reflect persistent concerns about the slow pace of economic growth. Economic data Thursday confirmed that the economy grew only 1.8 percent from January to March, a period when unemployment claims were higher than expected and consumer spending dropped.

The report dashed hopes that the economy was doing better than previously thought and led economists to downgrade their expectations for growth the rest of the year.

The competing visions seek to spur job growth by reducing the burdens on corporate America. Neither looks to use government spending to help reduce the country’s stubborn joblessness rate.

Obama’s plan builds on his remarks in the State of the Union address early this year that the United States must remain competitive in the global economy. He plans to emphasize that message while visiting a Chrysler plant in Toledo next week and holding a June 13 meeting in Raleigh-Durham, N.C., involving executives and other economic experts who sit on his Jobs and Competitiveness Council.

The Republican jobs plan is a shift from the party’s focus on cutting government spending and restructuring Medicare, goals that the Senate rejected 57 to 40 on Wednesday.

Although the party is not abandoning those positions, which have proven to be politically risky, GOP strategists are now testing a message focused on reduced taxes, deregulation and pro-business policies.

Both parties’ proposals are likely to be more about message than substance. Obama is trying to enlist the support of business in promoting job growth, in part because Congress is unwilling to spend more money to stimulate the economy. The GOP plan to reduce tax rates to stimulate the economy is likewise unlikely to pass muster in Congress given the opposition of many Democrats.

The Republicans have also called for free-trade deals with South Korea, Panama and Columbia, a position the Obama administration supports.

Obama’s regulatory proposals come after Obama signed an executive order in January requiring all federal agencies to review regulations and find those that are not worth their cost. The review is part of a renewed effort by Obama to cultivate ties with corporate America after a testy first two years in office.

“We are eliminating unnecessary regulatory burdens and tens of millions of hours in annual red tape,” Sunstein said.

One of the proposals, by the Occupational Safety and Health Administration, would ensure that required hazard labels and classifications in the United States are the same as those used in other countries, which could save companies $585 million a year.

Another, by the Environmental Protection Agency, would eliminate the requirement that states install systems to protect against fuel emissions at gas stations. Most vehicles already have these systems installed.

Other proposals would affect railroad safety, safety paperwork, exports and the input of data at hospitals.

“It appears the administration is making some common-sense recommendations that will save businesses some time, money, headaches, and resources. This is progress,” said Bill Kovacs, senior vice president at the U.S. Chamber of Commerce. “This is also not nearly enough. . . . They appear to have sidestepped the fundamental issues of cost and burden that have Republicans and Democrats alike clamoring for long-term regulatory reform.”

Staff writers Felicia Sonmez and Paul Kane contributed to this report.