Ahead of the Romney release, expected at 3 p.m. (1900 GMT), aides for the candidate said he earned almost $13.7 million last year and paid more than $1.9 million in taxes — an effective tax rate of 14.1 percent.

The tax release comes after a difficult week for Romney in which a leaked, secretly recorded video showed him saying nearly half of the country doesn’t pay income taxes.

Romney paid about $3 million in federal income taxes in 2010 — or 13.9 percent.

Critics, including President Barack Obama, have urged Romney to follow his father’s model. When George Romney ran for president, he released 12 years of tax returns.

Mitt Romney is refusing. He has said he is following the example of Republican Sen. John McCain, who released two years’ worth of returns in his race against Obama in 2008.

Democrats have tried to make an issue of what Romney pays in taxes and what he is willing to divulge about his taxes and investments.

His campaign had promised to release his complete 2011 returns before the election Nov. 6.

The vast majority of Romney’s income came from investments, which are taxed at a lower rate than wages. His wealth has been estimated as high as $250 million.

Obama’s tax return shows he earned nearly $790,000 last year and paid an effective tax rate of almost 21 percent.

On average, the wealthy in the U.S. pay higher income tax rates than those who make less. People making $1 million or more annually paid an average effective rate of 25 percent last year in federal income and payroll taxes, according to the nonpartisan Tax Policy Center, a Washington group that studies taxes.

The White House has argued that even so, some millionaires end up paying lower rates than many of those earning less. That is largely because many wealthy people earn income from dividends that are taxed at just 15 percent, instead of the top 35 percent rate on salaries.

A report in October by the Congressional Research Service, an agency that conducts research for lawmakers, said about a quarter of those earning $1 million or more per year — 94,500 taxpayers — had a lower tax rate than 10.4 million moderate-income people.

Romney proposes dropping all income tax rates by 20 percent, reducing the top tax rate from 35 percent to 28 percent. The bottom rate would go from 10 percent to 8 percent. Romney says he would pay for the rate cuts by eliminating or reducing tax credits, deductions and exemptions, but won’t say which ones would go.