A Bloomberg-era ban on students possessing cellphones in New York City public schools is being lifted, the Department of Education said Wednesday.

Under the policy shift, to be formally announced Wednesday afternoon by Mayor Bill de Blasio and schools Chancellor Carmen FariƱa, all 1.1 million of the city's public school students will be allowed to bring in cellphones and other electronic devices beginning March 2.

The city was expected to rescind the widely unpopular prohibition after the then-candidate made a mayoral campaign promise to do so in 2013. Last September, the mayor admitted that his son, Dante, routinely flouts the ban and carries a cellphone to Brooklyn Technical High School, where he is a senior.

Families long complained that the ban leaves them unable to communicate with their children during the school day and in cases of emergency. Advocates for the disadvantage lamented that the ban discriminates against poorer students, who were more likely to attend school in buildings where metal detectors are used.

Mona Davids, president of the New York City Parents Union, said in a statement: "We are glad the Mayor has embraced the perspective of parents, one that we have been championing for years. As parents, we will feel more comfortable knowing we can keep in contact with our children while they are commuting to school." She added, "Moreover, we are glad this unfair policy will be abolished, since it primarily disenfranchised students in communities of color."

A cottage industry of cellphone storage trucks outside the schools sprung up in the wake of the ban, charging students about $1 a day to store their cellphones.

Many educators, as well as now former Mayor Michael Bloomberg, steadfastly supported the ban, arguing that the devices enable cheating and cyberbullying and provided an unneeded distraction to education.

Principals will have wide discretion on how to implement the policy in their building, such as requiring they be out of sight, used only during designated times, or stored for the duration of the school day.

The rule change needs to be approved by the Panel for Educational Policy. Approval is expected.