The Montague Street subway tunnel, heavily damaged by Superstorm Sandy, will be closed for long-term repairs beginning in the summer, the MTA will announce today.

The shutdown of the R train route is expected to last 12 to 14 months, which carries tens of thousands of riders between Manhattan and southern Brooklyn.

Salt from storm surges heavily damaged electronic components in the tunnels and is still causing corrosion.

The MTA also plans to close a tunnel used by the increasingly popular G train between Brooklyn and Queens for 12 weekends this year.