Manassas Republicans could have one of the biggest conventions in their history Saturday as they gather to select a slate of candidates for mayor and City Council.

More than 800 delegates have signed up to vote, local party officials said, drawn by issues such as the economy and schools, competitive races and a conservative base attuned to the Republican presidential nominating process. Normally, about 300 to 400 Republicans show up at the GOP convention, party officials said.

“I think there’s a lot of enthusiasm by the Republicans in Virginia this year. A lot of our activists are dying to get out and start campaigning,” said Russell Harrison, a member of the city’s Republican Committee. The race between Mayor Harry “Hal” Parrish II and his challenger, council member Andrew “Andy” L. Harrover, for a spot on the Republican mayoral ticket is also drawing interest.

If history is any guide, Republicans will fare well in the May 1 election. All but one of the city’s six council members are Republicans; J. Steven Randolph is an independent.

Incumbent council members Jonathan L. Way, Sheryl L. Bass and Mark D. Wolfe will look to gain the support of Republicans against two challengers: Ian Lovejoy, a 30-year-old homeowners association member who works for a medical supply company, and Charles Patullo, a 56-year-old Montgomery County battalion fire chief who is head of Osbourn High School’s athletic booster club. The convention will be held at Grace E. Metz Middle School, and registration begins at 8 a.m.

Even though school board seats are nonpartisan and won’t be on the convention agenda Saturday, the city school system’s performance may well be.

“The school system takes the lion’s share of every tax dollar that comes in to the city,” said Steve Thomas, the Republican Committee’s vice chairman. “People are just wondering how effectively their tax dollars are being spent.”

Another issue that may come up Saturday involves questions of illegal immigration and the local ballet. The conservative blog Virginia Virtucon anonymously posted material Monday alleging that an illegal immigrant worked at the Manassas Ballet, where Wolfe is the executive director and Parrish and Bass serve on the board of directors.

Blogs that picked up the post put up a paper trail that showed that a Russian dancer, who was in the country on a visa to perform for a traveling Russian dance company, was denied a new visa that would have allowed him to join the Manassas Ballet, where he had auditioned.

The dancer appealed immigration officials’ decision and initially continued dancing for the Manassas Ballet while the appeal was pending, according to Wolfe and the ballet’s immigration lawyer. Wolfe said that in the bloggers’ effort to assail him, they omitted any mention of the appeal and the fact that the dancer was allowed to stay with the company while the appeal was pending.

Although he was allowed to stay, the ballet could not pay him directly during the appeal, Wolfe said. But through other dancers, he was given a “subsistence” for basic necessities, such as food and lodging, Wolfe said. Allowing others to help an immigrant while his status is pending is legal, said Cynthia Groomes Katz, the ballet’s immigration lawyer.

In the end, with the appeals process dragging on, the ballet let the dancer go.

“I feel bad what happened to the dancer, but Manassas Ballet followed the law,” Katz said. “To be accused of violating the law and not have the facts straight, that’s offensive.”

Wolfe said he is not sure whether the ballet issue will be a factor at the convention. But he’s likely going to focus on other issues, he said. “We’ve got to work together and improve our schools so people choose to move to Manassas, rather than move elsewhere,” he said.