MEMPHIS, Tenn. (AP) — More than two years of legal fighting, political acrimony and parental anxiety are culminating in a massive merger of the Memphis and suburban Shelby County school districts, but a key vote Tuesday could change the landscape of the new system after just one year.

The consolidation creates the Unified School District, a system of 150,000 students in Memphis and Shelby County, and officials are ramping up preparations for the start of classes next month. Experts call it one of the largest U.S. school consolidations in recent history.

But six majority-white suburbs of the smaller, successful Shelby County Schools district are eager to avoid the merger with the struggling, majority-black Memphis system. They've decided to try to start public districts of their own.

Tuesday will be the suburbs' second vote. In August 2012, residents approved separate districts, but a federal judge invalidated the vote. If approved, the six new systems could be up and running in 2014. Suburban voters and their mayors predict victory.

Christopher Myers said he and his wife moved to suburban Collierville from Memphis to provide his four children — including one with autism — a better education. He said parents are anxious about spending a year under a system joined with underperforming Memphis schools.

"The belief is that they're not up to the standards we have in Shelby County," he said. "You put inferior with superior or excellent, you're going to get something less than optimal. Is that really fair?"

Critics say the suburban separation would cause a dent in the massive consolidation efforts, including intense budget battles and layoffs of hundreds of teachers and office employees. Efforts have been hindered by accusations of foot-dragging, political sniping and racial discrimination.

"It's all being done at the last minute," said David Pickler, who sits on the 23-member Unified School Board. "That lack of stability certainly does not send a message of confidence to parents, to administrators. We've gone from trying to create a world-class school system to try to see if we can survive and move forward in a year that will set the foundation for an additional year of instability."

After 160 years in operation, Memphis City Schools gave up its charter in December 2010, forcing the merger with Shelby County. City voters approved the merge in March 2011. Supporters said it was necessary to preserve funding for the Memphis district, where inner-city schools were receiving D and F grades from the state.

A transition planning commission made recommendations to the merged division's board. U.S. District Judge Samuel Mays oversaw the transition. He mandated the number of seats on the board and was responsible for overturning the first vote for separate suburban districts as part of a lawsuit filed by the city of Memphis and Shelby County Commission.

In November, Mays ruled that the law that allowed the vote was illegal. But legislators in Nashville passed a second law, clearing the way for Tuesday's vote.

But Mays has not heard arguments on another accusation in the same lawsuit — that the suburbs want to break away for racial reasons. The city of Memphis and the Shelby County Commission say the move would create districts that are segregated along racial and socio-economic lines. It's not clear when, or if, Mays will address that part of the lawsuit.

Memphis is 63 percent black, with a median household of income $43,812, according to census data. The six suburbs — Arlington, Bartlett, Collierville, Germantown, Lakeland and Millington — are 80 percent white with a median income of $88,036. Suburban mayors and residents have denied any racial motivation.

Erica Frankenberg, an assistant professor at the College of Education at Penn State University, said the merger has major implications for state and local education policy issues. It raises questions about school funding and the implications of diversity, she said.

"What's unique about Shelby is the quickness with which this happened, but regional merger-consolidation efforts today hinge on the continued buy-in of suburban districts to succeed, and sometimes that can be difficult," she wrote in an email.

In August, when students take their first class under the new district's banner, they'll notice few changes. Most won't have to switch schools.

Basil Alter, 13, a rising 10th-grader at Overton High School, said there hasn't been much talk among his friends about the merger or vote. "Most people that I go to school with don't think about it," he said. "The teachers, I know they are very concerned about it."

As the second vote looms, the Unified School Board has been charged with the complicated planning process, including recommending a budget to the Shelby County Commission.

In its first year, the Unified School District will have about $1 billion to work with — about $75 million less than the premerger budgets of the city and county combined.

More than 900 teachers were not retained, though some of those positions are being filled. Another 200-plus office positions were cut, as were 600 non-teaching school jobs and 200 operations positions, according to the Unified School District. Teachers who have jobs in the new district worry about confusion over curriculum, evaluations and pay.

The board has decided on policies ranging from school uniforms to extracurricular activities and cellphones in class. It addressed many issues at a late June meeting, weeks before the start of class.

Pickler acknowledged that some issues should have been dealt with already. For months, the board worried about what he termed "political issues" — such as conducting, then suspending, a national superintendent search — rather than focusing on academics, he said.

"I did not recall one single conversation that we were making decisions to improve education quality," Pickler said. "I did not hear one conversation about how we're going to be more effective, more efficient in how we deliver education."

Kenneth Whalum, a former Memphis City Schools board member who sits on the new board, opposed the merger. He said he's frustrated that no planning has been done for the potential loss of more than 25,000 students, and the tax money and teachers that follow them, if the suburbs start their own systems.

Asked whether he thinks the board will be ready for the Aug. 5 start of school, Whalum said, "Absolutely not."

"I foresee a worsening of the economic conditions that we have now and certainly a worsening of the political conditions, and certainly a worsening of the delivery of education services," Whalum said.

Interim superintendent Dorsey Hopson has been under the microscope since he took the job in January, two years into the planning process. He recently told reporters that details like bus schedules are keeping him up at night.

"The grind every day, thinking about it and worrying about it, is tough," Hopson said.

In an earlier interview, Hopson said he reviews a checklist of areas of concern in each area of the county daily. He said he's confident the new district will be ready to go.

Unified School Board member Martavius Jones, who voted for Memphis to surrender its charter, said most everything will be ready for the school year, but some hiccups are likely.

He said that even after a split, the unified district would have more than 100,000 students.

"I don't think that it's a productive exercise to focus on who is leaving, rather than focusing on those that you're going to retain," Jones said.