With Assembly Member Michael Gianaris announcing Monday that he would run for the State Senate seat being vacated by George Onorato, a number of potential candidates are already eyeing Gianaris’ western Queens Assembly seat.

Aravella Simotas, a Democrat who is an attorney at the Manhattan firm of Bickel Brewer, appears to be the candidate most seriously considering a run so far.

Simotas and Gianaris are seen as having a close relationship: they are neighbors in Astoria, and as a one-time aide to Council Members Peter Vallone Jr. and Peter Vallone Sr., Simotas has worked closely with Gianaris—especially on a number of environmental issues.

She has already retained the services of the Parkside Group, which released a statement to City Hall on her behalf saying she is “exploring a candidacy for the Assembly in consultation with my family and community leaders.”

Candidates who retain Parkside as a consultant tend to be those with the backing of the Queens County Democratic Party. But the party’s executive director, Michael Reich, said it was far too early for the county party to make any kind of a decision. According to him, Simotas’ retention of Parkside should not be seen as an indicator that she would run with the county organization’s backing.

“Just because she’s with the Parkside Group means nothing to us,” Reich said. “We don’t dictate who they support and they don’t dictate who we support.”

Reich said that the likely frontrunner for the Assembly seat, in the unlikely events she decides to run, would be Anne Marie Anzalone, a district leader who works as chief of staff for Rep. Joe Crowley, the Queens Democratic leader. Reich, however, said he believes Anzalone is unlikely to run.

Anzalone did not return an email and call requesting comment. A Crowley spokesperson could not immediately make her available for comment.

Another potential Democratic candidate is Costa Constantinides, a legislative aide for Council Member Jim Gennaro. Constantinides is the president of the Queens County Young Democrats and a district leader.

“It’s definitely something I’m thinking about,” Constantinides said.

Constantinides is seen as having strong support from many of the younger active local Democrats.

Republicans, meanwhile, believe they have a shot at putting up a serious challenge for the seat, which covers a relatively conservative area. The district contains a large number of one- and two- family homes and features some socially conservative ethnic enclaves, including Italian, Greek, Irish, Croatian and Albanian communities.

Tom Dooley, a firefighter and Desert Storm marine veteran who ran against Onorato in 2008, is one possibility, a local Republican source said. Another possibility is Robert Hornak, the Urban Elephants blogger and former Assembly minority staffer who ran unsuccessfully for Queens borough president last year.