WASHINGTON — Republican presidential candidate Newt Gingrich paid $994,708 in federal taxes in 2010 on more than $3.1 million in income.

Gingrich disclosed his tax returns Thursday evening — minutes after the start of the televised Republican presidential debate — showing that the former House speaker owed roughly 31.6 percent of his adjusted income in taxes. Gingrich took aim at rival and multimillionaire Mitt Romney this week after Romney — who is worth more than $250 million — said he paid only 15 percent of his income in taxes.

Gingrich gave $81,133 in cash or checks to charities, about 2.6 percent of his income. That is considerably less than the average of $259,692 that households earning at least $2 million a year gave in 2009 to charities, according to research from the Center on Philanthropy at Indiana University.

Personal financial disclosure forms filed last summer show Gingrich is worth more than $6.5 million. He reported at least $500,000 in assets from Gingrich Productions, his media company that produces books and films.

The election is taking place during a critical time in the American economy, when voters say jobs are among the most important issues in deciding whom they want in the White House.