Some House Democrats are privately voicing frustration about Boston, this year’s host city for the party’s national convention, suggesting that the city won’t be able to provide the perks that Members have come to expect.

Drawing the most fire are Boston’s limited hotel space and the relatively small crowd capacity of the main convention site, the Fleet Center, according to Democratic sources both on and off Capitol Hill. Among many Democrats, Boston is considered a mid-size city — a smaller host locale than Chicago and Los Angeles, which hosted the 1996 and 2000 Democratic conventions, respectively.

While convention officials already have lined up credentials and hotel accommodations for Members of Congress, “superdelegates” to the convention, those same lawmakers worry they will be unable to get their friends, family and top donors plum housing slots and arena credentials.

“The hotel situation is a mess — there aren’t enough rooms,” said a Washington-based Democratic strategist. “Also, the Fleet Center is smaller and there are fewer credentials to give out. The Democratic National Convention Committee is having to make really tough decisions.”

Democratic sources say convention planners are already looking at creative ways to secure more housing nearby — even asking wealthy Bostonians to offer up their mansions for the week.

Those sources say that officials have assured delegates that they will have to stay no more than 3.5 miles away from the Fleet Center. Such a move is seen as critical given that much of Boston’s road and transportation network will be shut down during the week’s events, which will run from July 26 to 29.

Members and other prominent officials already are expected to rely on foot travel and public transportation to get around.

“Not everyone is going to be in the heart of the city,” acknowledged one senior Democratic Member who requested anonymity. “There will be inconveniences.”

Officially, Members will get the same number of credentials this year as in the past — one for themselves and one for another person. Members, however, are used to scoring additional passes.

“Credentials are tight” this year, said one veteran Member. “People are not happy about that. This is not the way to expand the party. We need a big tent.”

But Peggy Wilhide, communications director for the convention, said despite the Member concerns, lawmakers and their friends will not be slighted this year. She said while Boston is a smaller city and the Fleet Center has “slightly fewer skyboxes,” planners have secured the same number of Member credentials and hotel rooms as they did in Los Angeles four years ago.

Suitably located hotel rooms, in particular, will be available to priority attendees including delegates, their friends and family, and key Democratic allied groups, she said.

“I think it will be the same as in LA and in past conventions,” Wilhide said.

Democratic Caucus Chairman Bob Menendez (N.J.), co-chairman of the convention’s credentials committee, said convention planners are working overtime to ensure the Members’ needs are met.

“It’s going to be an excellent convention, whatever logistical challenges we have,” he said. “People are so excited about taking back the majority that we will overcome any logistical challenges Boston presents.”

It remains unclear how many people will be able to be credentialed for this summer’s events at the Fleet Center. The arena has an official capacity of 19,600 and seats slightly less for sporting events.

By contrast, the Staples Center in Los Angeles has an official capacity of 20,500, a number that in 2000 was reduced to 18,000 by the Democrats’ elaborate staging. But officials said that total was sometimes surpassed.

Convention planners and members of the Massachusetts delegation defended Beantown as a venue for the convention. They say they are confident any gripes by Members will wane by the time the convention begins.

“We will work those things out,” said Rep. Bill Delahunt (D-Mass.). “My own sense is that when attendees leave they will have a very positive impression and reflect on it as one of the great conventions and of America’s greatest cities.”

Delahunt added that convention cities always face challenges, noting that Los Angeles posed major transportation problems because of its size and layout.

On the flip side, he said, Members should be able to walk easily throughout downtown Boston and enjoy its offerings.

Rep. Richard Neal (D-Mass.) said “there is always hand-wringing” in advance of a convention. But those issues, he added, are always resolved.

“After 20 years of negotiating the Big Dig” — the years-long development of burying a major highway through the heart of Boston — “we’re going to get through these problems,” Neal said. “We’ll use creativity. We’ll sort through these things.”

Another Democratic lawmaker said the Massachusetts delegation is feeling the heat from its colleagues but doing a good job working to soften the early frustrations.

“Members from the Massachusetts delegation are under a great deal of pressure,” said the House Democrat. “Boston is a mid-size city. It’s not New York, Los Angeles or Chicago. Certainly efforts are being made so Members get what they want.”

As part of that effort, key Democratic sources suggested, convention planners will work to get attendees the best hotel rooms and secure more credentials. Members, those sources said, will work within their delegations to make trades for passes, as well as with state officials to try to get additional credentials for top constituents, donors and backers.

“Members have always cut deals to get more credentials,” said one Democratic Congressional aide. “It’s just going to be harder to do this cycle.”