Lobbyists typically open their wallets as a way to get close to Members.

But this week, K Streeters are expected to cut checks in droves for the chance to mingle with about 50 senior House staffers who are headlining a Democratic Congressional Campaign Committee fundraiser.

The fourth annual event doesn’t come cheap. Individual attendees are expected to shell out $1,000, while political action committees need to come up with $2,500 to score a seat at the sit-down dinner Thursday at Hotel Monaco.

But lobbyists say it’s worth the price tag to get a rare kind of access with high-level staffers.

Top aides to the Democratic leadership team — including John Lawrence and Jerry Hartz for Speaker Nancy Pelosi (Calif.), Terry Lierman and Stacey Bernards for Majority Leader Steny Hoyer (Md.), and Yelberton Watkins and Mike Hacker for Majority Whip James Clyburn (S.C.) — were among the 57 senior staffers listed on an e-mail reminder sent out by the DCCC last week to entice downtown donors. Ditto for George Shevlin for Democratic Caucus Chairman John Larson (Conn.) and David Weaver for DCCC Chairman Chris Van Hollen (Md.).

Senior committee aides such as John Buckley and Janice Mays of the Ways and Means Committee, Tom Kahn of the Budget Committee and Lesley Turner of the Appropriations panel were named as “invited” on the e-mail.

While the DCCC declined to name which staffers are confirmed to attend the dinner, about 50 senior-level aides are expected to be there, according to a source familiar with the event.

Several lobbyists who plan to attend say the fundraiser, which has collected almost $250,000 in the past, is the best DCCC event of the year.

But proffering up access to senior staffers, many who usually do not participate in political activities, has raised the ire of ethics and campaign finance watchdogs.

“This is just one more example of how the influence-money system works in Washington and why it is essential to establish a system of public financing for Congressional races,” Democracy 21 President Fred Wertheimer said.

Even so, the DCCC says it’s not doing anything wrong.

“These types of fundraisers are completely appropriate, and we appreciate everything senior staff does to maintain a strong Democratic majority,” DCCC spokesman Ryan Rudominer said. “These are off-time, volunteer activities by staffers committed to maintaining a strong Democratic majority.”

And the ethics concerns don’t seem to dampen K Street’s enthusiasm for the dinner.

The event has become an even hotter ticket as lobbyists have fewer chances to interact with staff in social settings following ethics restrictions that bar lobbyists from paying for most staffer entertainment and restaurant tabs.

Podesta Group’s Jaime Harrison, who attended the event when he was director of floor operations and counsel for Clyburn, is planning on going Thursday.

“There are a lot of folks out here on K Street who used to be former staffers,” Harrison said. “It’s a good opportunity to meet new staff that maybe you don’t have a relationship with or maybe you haven’t met.”

A Democratic aide also downplayed the scrutiny of outside groups.

“Raising money is part of the job,” the aide said, noting that it’s the same people who have been “wringing their hands” over the event for the past four years who are crying foul now.

“It’s a once-a-year event,” the Democratic aide said. “I think a lot of people make one ask a year, and this is the ask they make.”

Rick Kessler of Dow Lohnes Government Strategies also minimized the amount of official business that actually gets done at dinners like this.

“When you are at something that big, it makes the likelihood of something untoward happening much smaller,” Kessler said. “It’s not intimate in that sense. There’s very little business or shoptalk that I would engage in. It doesn’t feel right.”

The DCCC is hardly alone in using senior-level staff to bring in campaign contributions.

The National Republican Congressional Committee has also done two chiefs-of-staff fundraisers this year. The NRCC’s events on April 15 and May 26 were held at Cornerstone Government Affairs, although the NRCC paid to rent the space and for the food and drink, according to a committee official.

The NRCC also does not specify a contribution amount. Instead, the NRCC allows individuals to give at their discretion, the official said.

The Senatorial campaign committees of both parties also do a series of chiefs-of-staff fundraisers throughout the year. The National Republican Senatorial Committee most recently hosted such a fundraiser on April 15.

Using staff as a draw for fundraisers is within the bounds of the law, according to ethics lawyers. “Setting aside the appearance or optics of such invitations, there are no legal implications to such an event,” said Ken Gross, an ethics lawyer at Skadden, Arps, Slate, Meagher & Flom.