Washington, Apr 16 (AFP) Self-described Democratic socialist Bernie Sanders, the 2020 presidential candidate who has long assailed America's growing income inequality, released 10 years of tax returns Monday that confirm his newfound status as a millionaire.

The senator, who routinely rails against "millionaires and billionaires" and the "rigged" economic system that protects their standing, saw his income spike on royalties from sales of his book, "Our Revolution," published shortly after his 2016 race for the Democratic nomination.

According to tax returns released by the Sanders campaign, Sanders had an adjusted gross income of $561,293 in 2018, $1,131,925 in 2017 and $1,062,626 in 2016.

His 2015 income was substantially less, at $240,622, the returns showed.

"These tax returns show that our family has been fortunate. I am very grateful for that, as I grew up in a family that lived paycheck to paycheck and I know the stress of economic insecurity," Sanders said in a statement.

"I consider paying more in taxes as my income rose to be both an obligation and an investment in our country."

The increased wealth of the liberal candidate who has positioned himself as a champion of the people has raised questions about whether he can still speak for working-class Americans.

Sanders said he will still "strive every day to ensure every American has the basic necessities of life, including a livable wage, decent housing, health care and retirement security." The release comes amid continued pressure on billionaire President Donald Trump to show his tax returns.

The New York real estate tycoon refused to do so during the 2016 campaign, saying that he was under audit, but the Internal Revenue Service has said this is no impediment to their release.

Democrats have seized on the issue of Trump's undisclosed taxes since taking control of the House of Representatives in January, and have cited a little-known law that allows Congress to review anyone's returns to conduct an investigation.

On Saturday, Democratic lawmakers gave tax authorities a final deadline of April 23 to hand over Trump's returns, but it remained unclear if his administration will comply. (AFP)

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