TRANSPORT union members are to be balloted for strike action at Southampton port's main rail freight operator in a year long dispute over rosters and restructuring.

RMT union General Secretary Bob Crow said last night he was confident they would return a “massive yes vote” for industrial action at the depot in the city docks.

The ballot will open May 16 and close on May 30.

Freightliner has an 80 per cent market share of container rail freight at Southampton, transporting more than 1,000 containers out of the docks every day that would otherwise be taken by lorry.