The rail operator said staff could be more productively employed

The Rail Maritime and Transport union (RMT) said cuts would leave stations "severely understaffed", and undermine members' safety and performance.

The rail operator said ticket sale patterns had changed, and 90 jobs would be created with redeployment offered.

South Eastern Trains (SET) took over rail services in Kent and Sussex after Connex lost the regional franchise.

Vending machines

RMT general secretary Bob Crow said: "It all adds up to our members and the travelling public being asked to pay the price of re-privatising South Eastern Trains with jobs and service levels.

"RMT has made it quite clear that we reject these plans and the resulting loss of jobs and undermining of our members' safety, and will resist with industrial action if necessary."

The rail operator said ticket office staff could be more productively employed at quiet times and new jobs would improve security, station presentation and revenue protection.

A spokesman said new ticket vending machines were being installed at stations which could issue a full range of tickets and take credit cards, so passengers could buy tickets when offices were unstaffed.

He added proposals were not yet final and consultation was under way with rail industry watchdogs.