Massachusetts Senator John Kerry Thursday called on the FDA to end its lifetime ban on blood donated by gay men.

Seventeen Democratic lawmakers joined Kerry in asking FDA Commissioner Margaret Hamburg to reverse its policy.

“Not a single piece of scientific evidence supports the ban,” said Kerry in a statement. “A law that was once considered medically justified is today simply outdated and needs to end, just as last year we ended the travel ban against those with HIV.”

In the letter, the lawmakers argue that the ban specifically singles out gay men and is “scientifically unsound.”

“Prospective donors who have engaged in heterosexual sexual activity with a person known to have HIV are deferred for one year. At the same time, male donors who engaged in protected homosexual sexual activity with a monogamous partner 26 years ago are deferred for life.”

“The ban also does not distinguish between safe and unprotected sexual activity. As a result, healthy blood donors are turned away every day due to an antiquated policy and our blood supply is not necessarily any safer for it.”

The policy, which rejects men who have had a sexual relationship with another man since 1977 from donating blood, is unnecessary because of technological advances, the lawmakers say.

“We live in a very different country than we did in 1983. Today, the high-risk behaviors associated with HIV contraction are more fully understood and dramatic technological improvements have been made in HIV detection. … As a result [of screening], the blood banking community believes that the lifetime deferral is no longer necessary to protect the integrity of the blood banks.”

In addition to Kerry, the letter was also signed by Democratic Senators Kirstin Gillibrand of New York, Dick Durbin of Illinois, Daniel Akaka of Hawaii, Sheldon Whitehouse of Rhode Island, Sherrod Brown of Ohio, Frank Lautenberg of New Jersey, Bob Casey of Pennsylvania, Bernie Sanders of Vermont, Russ Feingold of Wisconsin, Mark Udall of Colorado, Al Franken of Minnesota, Maria Cantwell of Washington, Carl Levin of Michigan, Tom Harkin of Iowa, Mark Begich of Alaska, Roland Burris of Illinois and Michael Bennet of Colorado.