A bill introduced in the Senate today would require presidential nominees to release three years of tax returns.

Sen. Ron Wyden, D-Ore., introduced the Presidential Tax Transparency Act today, saying in a statement: “Since the days of Watergate, the American people have had an expectation that nominees to be the leader of the free world not hide their finances and personal tax returns.” Wyden is the ranking Democrat on the Senate Finance Committee which has jurisdiction over matters involving tax policy.

The bill, which you can read here, was introduced as a stand-alone measure, but a spokeswoman for Wyden told The New York Times that it would also be “put forward as an amendment to the annual military policy bill to increase its chances of getting a vote.”

A recent poll from The New York Times and CBS News showed a strong majority of registered voters think it is necessary for presidential candidates to disclose their tax returns.

The Sunlight Foundation recently called on Congress to pass such a bill:

Just as presidential candidates are required to submit personal financial disclosure forms to the Federal Election Commission, they could be required to submit their tax returns for public review. An orderly, enforceable, rule-based process would let us skip the drama and doubts, and ensure access to what we already expect of our candidates: a reasonably clear view into their financial lives.

Although all candidates over the past 40 years have voluntarily released some tax returns, they have not been required to do so. And some have released fewer than the three years that would be required by this bill: Mitt Romney and John McCain both released only two years of returns in their presidential campaigns. Donald Trump’s refusal to release any of his returns would make him the first major party nominee since 1976 not to release tax returns.