Rail passengers are waking up this morning to a week of transport chaos as the five-day rail strike begins.

Less than 60 per cent of services from an already heavily reduced Southern rail timetable is set to run until the end of Friday after workers and rail bosses failed to agree on changes to conductors' roles.

Members of the Rail, Maritime and Transport (RMT) union have walked out, mounting picket lines outside stations, in an escalating row over the role of conductors.

Southern Railway services running from Watford Junction have been cancelled for four weeks now.

Southern's owner, Govia Thameslink Railway, apologised to passengers, describing the strike as "completely unjustified".

Talks at the conciliation service Acas collapsed last Friday.

The union had offered to suspend industrial action if the company agreed to an offer like the one made by ScotRail in a similar dispute but Southern said this was a "red herring".

RMT general secretary Mick Cash said: "The strike action this morning is rock solid across the Southern Rail network as we fight to put rail safety before the profits of the failed Govia Thameslink operation.

"This action has been forced on us by the arrogance and inaction of Govia Thameslink and the Government, who have made it clear that they have no interest in resolving this dispute or in tackling the daily chaos on Southern.

"We offered to suspend the action on Friday if they matched the offer we secured on ScotRail. They kicked that back in our faces.

"Our fight is with the company and the Government who have dragged this franchise into total meltdown.

"We share the anger and frustration of passengers and we cannot sit back while jobs and safety are compromised on these dangerously overcrowded trains."

Southern said it will run 60 per cent of trains in an emergency timetable from Monday. Some routes will have no services.