In the race for the Greater Boston resort casino license, Las Vegas developer Steve Wynn seems to have some momentum, but the city of Boston may be trying to trip him up.

Mayor Thomas M. Menino’s administration is suggesting that some of Wynn’s planned Everett casino development may be in Boston, which would give the capital city far more rights under the law to affect the project.

That would include the right for Menino, who backs a competing casino plan at Suffolk Downs, to simply kill the Wynn proposal and eliminate a competitor.

Wynn said he is confident that Everett — where voters backed his plans in a landslide last month — is the only community that hosts his $1.3 billion proposal on the Mystic River waterfront, and he responded sharply to Boston’s suggestion otherwise.

“Our company comes to the Commonwealth of Massachusetts expecting fairness and transparency, and we fail to understand Mayor Menino’s continued efforts to frustrate a project that has the power to transform the city of Everett, bringing economic opportunity that has eluded it for decades,” Wynn said in a statement released through his spokesman. “We understand that the mayor favors another horse in this race, but we intend to remain focused on our project in Everett. The governing legislation’s definition of a host community is straightforward. By any reading, the host community for our project is the city of Everett.”

The Menino administration raised its claims in a July 11 letter to one of Wynn’s local consultants, in which the mayor’s Host Community Advisory Committee wrote that discussions with Wynn representatives and environmental documents Wynn filed with the state “lead us to the conclusion that Boston would appear to be a host community to the proposed Wynn resort.” The city raised a similar assertion in a letter to Richard Sullivan, the state’s energy and environmental affairs secretary.

Boston’s assertion rests on the odd shape of the city line, which darts across the Mystic River in a thin finger into the edge of the former Monsanto chemical site where Wynn intends to build.

The 2011 state casino law defines a host community simply as “a municipality in which a gaming establishment is located” or proposed. A “gaming establishment,” under the law, is “a gaming area and any other nongaming structure related to the gaming area and may include, but shall not be limited to, hotels, restaurants or other amenities.”

Wynn’s plan calls for no buildings touching the city line, and Wynn has said he has no development plans in Boston. But the city is pursuing whether road, landscaping, or harbor improvements may cross the line and possibly elevate the city to a host community.

Political leaders of host communities have vast power to stonewall casinos by simply refusing to negotiate with the developer over the terms by which the community would accept a gambling business. That is how Foxborough officials forced Wynn to abandon resort plans in the town last year, which led to Wynn’s reemergence in Everett. Officials in Boxborough, Salisbury, and Holyoke have similarly forced casino developers to move on by declining to negotiate.

“I think the strategy would be to try to make Wynn go away,” said Clyde Barrow, a casino expert at the University of Massachusetts-Dartmouth. “That would be the cleanest way.”

Brian Leary, chairman of Menino’s casino advisory committee, said the committee wrote to Wynn in search of information, such as traffic studies and harbor plans, in order to properly advise the mayor on the possible effects of the project on Boston.

“The Host Community Advisory Committee doesn’t know whether the city of Boston is a host community [to the Wynn project], but in order to properly do our job we need to find out more about the development, where elements of development are going to touch the city of Boston line or go over it,” he said. “That’s why we’re asking for information from Wynn. We need to better understand what their development does.”

Disputes about whether any municipality is a casino host community would be decided by the state gambling commission, said Stephen Crosby, the commission’s chairman.

If Boston is not a host community, it probably would qualify as a “surrounding” community under the law, which would entitle the city to negotiate compensation with Wynn for the possible effects of the development. Surrounding communities, however, cannot kill projects by refusing to negotiate.

Wynn and Suffolk Downs are competing for the sole Greater Boston resort casino license. There is one other competitor: Foxwoods, which is planning a casino in Milford.