Bay Ridge subway riders may finally be getting some ‘R’elief.

The R train could begin operating under the East River by the end of the week for the first time since Hurricane Sandy hit, MTA officials said yesterday.

Transit workers are making repairs on the heavily flooded Montague Street Tunnel — which the R uses to travel under the East River — around the clock, said Carmen Bianco, senior vice president of subways.

“We hope to get that [running] by December 21,” Bianco said at the MTA’s monthly Transit Committee meeting.