WASHINGTON — The top 1 percent of earners more than doubled their share of the nation’s income over the last three decades, the Congressional Budget Office said Tuesday, in a new report likely to figure prominently in the escalating political fight over how to revive the economy, create jobs and lower the federal debt.

In addition, the report said, government policy has become less redistributive since the late 1970s, doing less to reduce the concentration of income.

“The equalizing effect of federal taxes was smaller” in 2007 than in 1979, as “the composition of federal revenues shifted away from progressive income taxes to less-progressive payroll taxes,” the budget office said.

Also, it said, federal benefit payments are doing less to even out the distribution of income, as a growing share of benefits, like Social Security, goes to older Americans, regardless of their income.