WASHINGTON — The Obama administration is proposing tougher restrictions on brokers who manage Americans’ retirement accounts, reigniting a confrontation with the financial services industry over rules affecting trillions of dollars in 401k and other savings accounts.

The change would put brokers — who sell stocks, bonds, annuities and other investments — under the stricter requirements for registered financial advisers when they handle clients’ retirement accounts.

In a long-anticipated move, the Labor Department is making the proposal today to the White House Budget Office. After an internal review, it likely will be put out for public comment for several months.

The rule has been the subject of intense behind-the-scenes lobbying, pitting major Wall Street firms and financial industry groups against a coalition of labor, consumer groups and retiree advocates such as the AARP.

The administration first proposed a regulation in 2010, but pulled it back following an industry outcry that the proposal would hurt rather than help investors by limiting choices.

To buttress the new effort, the White House is releasing a report from its Council of Economic Advisers that concludes investors lose billions of dollars because of brokers’ conflicts of interests. Obama was scheduled to address the AARP later today to draw attention to the plan.

“When you go to a doctor or a lawyer, you expect the advice you get to be in your best interests. But the same doesn’t always hold true in the world of retirement savings,” Labor Secretary Tom Perez said in a conference call with reporters. “Many financial advisers have taken an oath to serve your best interests, but there are other financial advisers and brokers who provide critical financial advice every day and are not obligated to look out for your best interests.”

Americans increasingly are seeking financial advice to help them navigate an array of options for retirement, college savings and more. Many people provide investment advice, but not all of them are required to disclose potential conflicts of interest.

Under current rules, brokers are required to recommend only “suitable” investments based on the client’s finances, age and how much risk is appropriate for him or her. The rules would make brokers handling retirement accounts obligated to put their clients’ interests first.

The chairman of Obama’s Council of Economic Advisers, Jason Furman, pointed to academic studies that conclude investors who receive investment recommendations potentially influenced by conflicts of interest sustain a 1 percentage point lower return on their retirement savings, totaling losses of $17 billion every year to middle-class families.