Phillip Wong moved to the U.S, from Hong Kong with his family in 1974. That was just about the time mainland China announced it intended take back the colony from Britain when its treaty expired in 1997

The announcement set off a 20-year-long exodus from Hong Kong to New York and elsewhere that changed the size and nature of the Asian-American community here.

This week, Wong, who lives in Elmhurst, was one of three parents who filed suit against Mayor de Blasio and Schools Chancellor Richard Carranza on behalf of his eighth-grade daughter.

The suit alleges that city officials are illegally holding down the number of Asian students admitted to the city’s “elite-eight” high schools in order to increase enrollment by black and Hispanic students. It is one of the most bitter issues dividing the city right now and a political line in the sand for Queens.

Wong, who works as a translator, directed all questions about his role in the case to the Pacific Legal Foundation, the pro bono law firm that is handling the suit against de Blasio.

A spokesman for the firm said Wong was “one of the first people who contacted us” last October when the lawsuit was in its preliminary stages.

Wong’s daughter, indentified in court papers only as “A.W.,” attends IS 5, the Walter H. Crowley Intermediate School in Elmhurst. She like other young hopefuls took the controversial Specialized High Schools Admissions Test last October.

In March, she will hear whether she has made the cutoff for the elite schools, including Stuyvesant High School, Bronx High School of Science and Brooklyn Technical High School.

If she does not make the cut, the suit claims, it may well be because the city changed the Discovery program — aimed at getting more minority students into the top schools — to discriminate against her.

That is what the landmark lawsuit, filed in Manhattan federal court last Thursday by several Asian-American groups, the Parent-Teacher Organization of Christa McAuliffe High School in Brooklyn and the parents of three eighth-graders — including Phillip Wong — is about.

Much of the Asian community has been in an uproar since de Blasio and Carranza said last year that they intend to get rid of the SHSAT as the sole determining factor for admission.

However, they need a change in state law to do that. So instead, the mayor and chancellor this year revised the longstanding Discovery program — created more than 20 years ago to help minority students who just missed the cutoff scores get into the elite schools.

Five percent of the seats in the ninth-grade class used to be set aside for Discovery students. For the next school year, that percentage was summarily raised to 20 percent.

The lawsuit filed last week contends that change is unconstitutional because, in effect, it takes seats away from Asian students who would have made the cutoff and gives them to black and Hispanic kids.

Under the old plan, 17 of 22 schools in Queens with a majority of Asian eighth-grade students were eligible for the second-chance Discovery program, if they were a few points shy, according to the PLF.

Under the mayor’s new plane, only 11 majority-Asian schools qualify.

The most affected school in Queens is Nathaniel Hawthorne Middle School 74 in Oakland Gardens. More than 66 percent of the 417 students in eighth grade there are Asian American, the law firm says.

Last year, students there were eligible for a second chance. Now they are not, said Chris Keiser, a lawyer for PLF.

“It’s a game changer,” David Lee of the Chinese American Citizens Alliance for Greater New York, one of the groups suing the mayor, said. “This is a federal-level spuit that could go to the Supreme Court. It’s going to take the veneer off what the mayor and everyone else has been doing.”

Former City Controller John Liu, who unseated state Sen. Tony Avella in the district representing Bayside and Whitestone, called the suit “one of many and varied reponses to this boondoogle.”

“The fact that this is an organic, grassroots, pop-up effort speaks volumes,” said the state senator-elect. “It’s a strong indication of just how the public feels.”