U.S. Rep. Keith Ellison could use some advice on transparency in government. Fortunately, he's on friendly terms with two good sources: Sen. Amy Klobuchar and Rep. Tim Walz, two Democratic colleagues who have decided not to accept privately funded travel while in Congress.

Once enlightened, Ellison should quickly release all available details about a fall 2008 trip he took to Mecca courtesy of the Muslim American Society of Minnesota.

Ellison cleared the 16-day trip with the House Ethics Committee, but he has declined to reveal how much he spent on travel, food and lodging. That leaves him wide open for the type of attacks Klobuchar and Walz must have anticipated when they made their 2006 pledges to steer clear of trips that could present real or perceived conflicts of interest.

Ellison's office has maintained that the Mecca trip was "personal," but it also says the Ethics Committee is revisiting the question of whether the costs must be reported.

Ellison, a second-term congressman, is making a freshman mistake. If he has nothing to hide, why is he declining to release a detailed summary of his expenses? And why has he refused to release the entire letter from the Ethics Committee explaining why the trip was approved?

Under the 2007 ethics reform legislation, lobbyists are prohibited from sponsoring trips for members of Congress. Nonprofit entities, such as the Muslim American Society, can cover the costs of such trips, but the travel is subject to ethics guidelines that require detailed disclosure.

Despite what you might hear on partisan talk radio or read on some blogs, this kind of travel is both common in Washington and bipartisan. Many trips are sponsored by nonprofit organizations that are holding events on issues related to congressional committee work or legislative agendas.

What makes the Ellison case unusual is his refusal to put a price tag on the trip. The Ethics Committee has a policy of not commenting on individual cases, so it's up to the Fifth District congressman to clear up the confusion.

When Ellison arrived in Washington in January 2007, ethics reform topped the agenda for congressional Democrats, who were reacting to polls showing that scandals motivated 42 percent of voters in the 2006 elections. Transparency remains a concern for voters, and in his handling of the Mecca trip, Ellison is at a minimum revealing a lack of experience in dealing with the disclosure issue.

Klobuchar, who made ethics a central theme in her campaign, wanted Congress to ban all privately financed trips, not just those paid for by lobbyists. Walz, who joined Ellison in the 2006 freshman class, argued that congressional travel, if warranted, should be financed by public money.

But until Congress adopts stronger ethics rules, privately funded trips such as Ellison's Mecca trip will remain controversial -- especially if public officials are stingy with the details.

U.S. Rep. Keith Ellison, D-Minn.