It’s time to shutter Capitol Hill’s infamous revolving door of retiring federal lawmakers transitioning into the lobbying industry, U.S. Sen. Michael Bennet says.

“Washington has become all too comfortable with the spin of the revolving door,” said Bennet, a Democrat from Colorado, in a statement.

About 51 percent of legislators from the 113th Congress that found employment after retiring have become lobbyists – powerful, influential voices in the ears of federal lawmakers – according to a study by the Sunlight Foundation and the Center for Responsive Politics. And despite current lobbying restrictions, many lawmakers and senior congressional staff have taken advantage of loopholes, and lobbied in the shadows, the non-partisan group found.

Bennet wants to buck the trend with new legislation introduced in the Senate last week that would ban members of Congress from ever becoming lobbyists. He has garnered support from co-sponsors U.S. Sens. Cory Gardner, R-Colo., and Al Franken, D-Minn.

The senators say the legislation would help limit lobbyist influence in Washington.

“This bill puts power back into the hands of the Coloradans I came here to represent,” Bennet said. “By banning members of Congress from lobbying when they leave Capitol Hill, we can begin to restore confidence in our national politics.”

Along with a lifetime ban, the legislation would increase congressional staff restrictions on lobbying from one year to six years, implement a 6-year ban on lobbyists from joining congressional or committee staff that they previously lobbied and create a more accessible website for public reporting of lobbying efforts.

“We need to close the revolving door between Congress and the lobbying industry because our democracy can’t function the way it’s supposed to when well-connected special interests have more power than the American people,” Franken said.

In 2007, then President George W. Bush signed into law the Honest Leadership and Open Government Act, requiring retiring senators wait two years – one year for members of the House – before becoming a lobbyist. The rule is comparable to those limits for the Colorado state Legislature.

The Center for Responsive Politics analysis found that while lobbying restrictions remain in place for lawmakers, they are more “spaghetti than steel.” Many lawmakers transitioned into government public relations jobs or served as counsel for a firm that lobbied during the so-called “cooling off” period.

The senators said the bill would strengthen disclosure requirements in an effort to rein in stealth lobbying.

It would require lobbying agencies to report on non-lobbyist employees who are former federal lawmakers or senior congressional staff and increase the maximum penalty for violating the Lobbying Disclosure Act.

“Through increased transparency, not just by federal lobbyists, but also by firms and companies that may have former members of Congress who are skirting the lobbyist line, the public will be better informed, and the lobbying profession will be deterred from undermining the common good,” the senators said in a statement.

Bennet has introduced legislation in the past aimed at reining in lobbying by former Congress members; that effort failed in committee.