Sadiq Khan says Southern Rail should be placed under Tfl control after months of commuter misery

London Mayor has written to new Transport Secretary Chris Grayling urging him to put network back into public ownership

Passengers stage a 'fare strike' and protest at Victoria Station in central London in response to Southern Railway's delays (Rex)

London Mayor Sadiq Khan has formally called for Southern Rail to be transferred back into public ownership after months of commuter chaos.

Mr Khan has written to the newly installed Transport Secretary Chris Grayling to asked for Transport for London (Tfl) to be put in charge of the service until the problems plaguing the network are resolved.

The company, owned by Govia Thameslink Railway (GTR) has cut 341 journeys a day from its timetable after weeks of staff shortages, sickness and industrial action.

Customers have reported overcrowded carriages and long delays as some said they face losing their jobs as they are unable to get to work on time.

The problems with the network were exacerbated on Monday afternoon after soaring temperatures caused a 50ft sinkhole to appear under the track at Forest Hill, forcing Southern and London Overground services to be suspended.

In a letter to Mr Grayling, Mr Khan said: "Thousands of Londoners and longer-distance commuters simply cannot get to and from work, and are understandably furious.

"There is no doubt that the franchise must now be in default, and I have previously called for your department to step in and take control.

Sadiq Khan has asked Chris Grayling to hand over control of the network to Tfl (AFP/Getty Images) (AFP/Getty)

"Notwithstanding the wider discussions on devolution, I now offer to go one step further and put my senior TfL team in charge of the Southern franchise until we get a permanent resolution."

GTR have blamed much of the disruption on industrial action by staff who are protesting against a proposal to make all services "driver-only" trains, meaning there will be no conductor and drivers will be responsible for closing all the doors themselves.

The company has accused members of the Rail, Maritime and Transport union (RMT) of staging an unofficial "sick leave" strike, meaning there weren't enough staff available to operate the services.

But RMT has dismissed the accusation as a "disgraceful campaign of misinformation".

General Secretary Mick Cash said: "Passengers and staff alike are being held hostage by this failed rail operation and the silence from the new team at the DfT is deafening.

"There has to be urgent action to remove GTR and bring in Directly Operated Railways before there is a major disaster."

Labour's transport spokeswoman on the London Assembly, Florence Eshalomi, said: "A TfL takeover is a sensible step towards addressing the problems plaguing Southern, which the Government have so far been content to kick into the long grass."

TSSA union leader Manuel Cortes said: "We support the London Mayor's offer and it would be a fast and efficient way to restore a proper level of service for long-suffering passengers who have been through hell these last few months."

A map of the revised Southern services after they cut the 340 trains a day (Southern Railway)

But the Department of Transport came down on the side of the train company saying RMT was "holding the traveling public to ransom" with their "completely unacceptable actions".

Rail minister Paul Maynard said: "The situation with Southern services must improve and I am pleased that it is beginning to reinstate some of the trains suspended to manage the impact of the RMT action."

Former Rail minister Claire Perry resigned over the chaos at London Bridge last week, saying she felt "ashamed" that she had been unable to sort out the problems on the network after months of fending off calls for GTR to lose their franchise.

More than 100 angry commuters staged a protest at Victoria station last week, holding up signs which read "#SouthernFail", "We pay, you delay" and "stand up to Southern - like we have to on their trains".

A GTR spokesperson said: "We sympathise strongly with our passengers who were caught up in the disruption caused by the temporary closure of Brighton station last night, and are sorry for the delays many experienced in getting home."

She added: "Train services across the whole of the South of England were affected by heat-related infrastructure problems yesterday, with many London terminals also experiencing crowding and delayed trains."

Additional reporting by PA