In a proposed redistricting, almost all communities in Massachusetts are represented by a single person in Congress. Cambridge, though, would be carved into two districts.

Only hours after his reelection, city councillor Leland Cheung was back at work Wednesday, raising the alarm about a congressional redistricting that would carve Cambridge in two — a central chunk being represented by U.S. Rep. Edward Markey as the 5th Congressional District and parts in North Cambridge and closer to the river being represented by U.S. Rep. Mike Capuano as the 7th Congressional District.

The map was released Monday by state lawmakers’ Special Joint Committee on Redistricting of the Massachusetts General Court. But things are moving fast.

“We only have until tomorrow for the public to comment,” Cheung said. “This undoubtedly hurts our standing in Congress because we’d go from being one-seventh of a district to one-fourteenth.”

Capuano represents all of Cambridge at the moment in the 8th Congressional District — a structure in place for seven decades that allows the interests of Cambridge, Somerville and Boston to be handled as one. A change in population reflected in recent census figures brought on the redistricting.

“Parts of Cambridge will be represented by someone who also needs to balance the needs of Revere, Chelsea and other urban areas, and other parts of Cambridge will be represented by someone who also needs to balance the needs of Southborough and other suburban areas,” said Susana Segat in her CCTV blog.

Cheung noted that “Capuano has his district office in Cambridge for a reason” and said “residents need to know to weigh in.”

By passing around tips from Daniel Schlozman, chairman of Cambridge’s Democratic City Committee, Cheung is trying to ensure that. With the deadline of 2 p.m. Thursday, people are urged to tell lawmakers they want Cambridge kept whole in the 7th Congressional District by:

Contacting Mike Moran, House chairman of the Joint Redistricting Committee, at at (617) 722-2460 or michael.moran@mahouse.gov.

Contacting Stan Rosenberg, Senate chairman of the Joint Redistricting Committee, at (617) 722-1532 or stan.rosenberg@masenate.gov.

Supplying written testimony to the Joint Redistricting Committee at malegislature.gov/District/Contact.

Schlozman can be reached at daschloz@gmail.com or (617) 519-8555.