Brighton commuters could face severe disruption if a planned 24-hour rail strike goes ahead.

Union members at First Capital Connect (FCC) are protesting after a worker who challenged a fare evader was sacked.

The strike, planned by members of the Rail Maritime and Transport union (RMT) for September 14, will affect services between Brighton and London.

Union members said they opted to strike after Rachel Lock was dismissed despite claiming she was assaulted by a passenger at a ticket barrier.

Bob Crow, the union general secretary, said: “We will not tolerate a situation where RMT members on revenue teams are treated in this callous and brutal way.

“It's a scandal that, instead of supporting their member of staff in this traumatic situation, they have chosen instead to sack her.

“With the train companies turning up the pressure for more and harsher penalty fares, they are putting more and more staff at the risk of assault of this kind.

“We are determined to secure a just outcome for Ms Lock but send out a clear signal to other staff running the daily risk of assault.”

FCC said Ms Lock, who was a member of the rail company's revenue team, would not be reinstated.

The rail company, which also operates services along the East Coast Main Line up to Peterborough, Cambridge, and King's Lynn, said it hoped to run “as near a full service as possible” during the strike.

An FCC spokesman said: “This is an unnecessary strike over the dismissal of an employee for gross misconduct.

“The incident was seen by several credible witnesses including an off-duty police officer.

“The safety and security of our staff is our absolute top priority and FCC has followed the disciplinary procedure agreed with the trade unions all the way through to appeal.

"Customers should be confident it will be business as usual on Monday.

We intend to run as near a full service as possible using fully trained and competent employees to cover for the mainly ticket office, ticket inspector and ticket gateline staff who will be on strike. “