A campaign to let Camden residents decide the fate of a controversial takeover of the city's police department by Camden County hit a roadblock Wednesday when the city filed an injunction seeking to block the referendum.

In a complaint filed in Superior Court, Camden attorneys argued that the decision whether to implement the plan is not up to voters and is within the sole authority of city and state officials.

The action comes three weeks after police-union officials and community activists submitted a petition with 2,800 signatures calling for an ordinance to block the police takeover, arguing it was a union-busting maneuver that would make the city unsafe by replacing veteran police with younger, inexperienced officers. Under state law, City Council — which was scheduled to meet on the matter next week — has to vote down the ordinance or put the matter to voters.

John Williamson, president of the Camden Fraternal Order of Police, said the union would fight the action in court.

"We look in other countries where the politicians go against the will of the people and we see revolutions every day," he said. "It is the right of the people to have a say in government. That's part of a democracy."

A city of violent drug corners and with a high homicide rate, Camden has vexed politicians and policy makers from City Hall to the governor's office. The latest plan, which has widespread support from top political figures, would seek to double the size of the city's police force by dismantling the existing department and establishing a county-run force that its backers say would be more efficient.

Only half of Camden's existing officers could be rehired and they would take substantial cuts in pay and benefits.

Union officials from across the state have opposed the plan. But with support for it from Gov. Christie, Camden Mayor Dana L. Redd, and powerful local Democrat George E. Norcross III, the only means to block its implementation was considered to be a citywide referendum — something politicians are eager to avoid. Norcross, an insurance executive and chairman of Cooper University Hospital in Camden, is an owner of Philadelphia Media Network, the parent company of The Inquirer.

The injunction was necessary to preserve safety, Redd said in a statement issued Wednesday evening.

"While we respect the rights of our voters and respect our law enforcement personnel, the safety of our citizens and the children and families of Camden must come first," she said.

Union leaders and activists, including the president of the Camden County NAACP, began collecting signatures for a referendum in December. The city clerk rejected their first petition on a procedural issue, but certified a second petition submitted April 11.

Attorneys for Camden have asked a judge to intervene, arguing that voters' right to a referendum on municipal issues is limited and cannot constrain how elected officials run the city. That is an argument that New Jersey towns and cities, which are granted significant autonomy under state law, have made before.

Camden is under state supervision after years of budget overruns. With little tax revenue, the city relies on state aid for two-thirds of its $180 million budget. In the legal brief filed Wednesday, city attorneys argued that because state officials support the takeover, state aid might be in jeopardy if Camden doesn't impose the plan.

The concept of a Camden County police department was pitched 16 months ago by County Freeholder Director Louis Cappelli Jr. as a force that would cover Camden and the surrounding region. But suburban mayors, wary of ceding control over public safety, balked.

Redd, a former state senator who took office in 2010, agreed in December to have Camden join the planned county department. After much of the city force was laid off in January 2011, homicides spiked in the fall, spurring fears that the officers left were powerless against warring drug gangs.

The homicide rate leveled off later in the year. So far in 2012, Camden had recorded 16 homicides, the same number as this time last year.

Contact James Osborne at 856-779-3876, jaosborne@phillynews.com or follow on Twitter @osborneja.