Senior politicians have made contrasting bids to apportion blame for the Southern rail drivers strike that has left 500,000 passengers without a service for the next two days.

London's Labour Mayor Sadiq Khan made a direct appeal to commuters via video, urging them to write to Prime Minister Theresa May in support of his proposal for Transport for London (TFL) to take control of commuter lines including Southern.

Speaking from City Hall, he said: "Southern commuters have been abandoned by the government. You've had months of chaos. But it doesn't have to be like this. There were originally two strikes planned this week. One on Southern rail, which is the responsibility of the government. And one on TFL, for which I am responsible. TFL engaged with the unions and the underground strike got cancelled."

Khan claimed to have reduced strike action on the TFL network by 92% since becoming mayor.

In Westminster, Conservative Transport Secretary Chris Grayling offered his assessment of the strikes, which will run for a total of three days this week, laying the blame firmly at the door of unions. He said: "We're not prepared to end the modernisation of the railway ... you have to use new technology, all other businesses know that. I don't understand why the unions are so resistant to what's going to make a difference in the modern world."

Khan's grab for suburban rail routes comes a week after a letter from Grayling to former Mayor Boris Johnson in which he explained his reluctance to devolve the lines in case they fell into "the clutches of a Labour Mayor" was leaked.

Drivers from the ASLEF and RMT began a 48hr walkout this morning in protest over Southern's plans to introduce driver only operated (DOO) trains. A further walkout is scheduled for Friday. They say that the implementation of DOO will jeopardize passenger safety but the government point out that around 30 per cent of the nation's trains are already DOO.

The Court of Appeal yesterday ruled against Southern's attempt to get an injunction against the strikes. Southern had claimed that the cancellation of all services would contravene the rights of passengers while unions argued that it was their members fundamental right to strike. Speaking after the judgment, ASLEF general secretary Mick Whelan, said: "Industrial action is always the last resort. We don't want to inconvenience the travelling public, and our members don't want to lose money. We are going on strike because we have been forced into this position by an intransigent management that has not been prepared to negotiate with us."

Commuters along the Southern network took to twitter this morning, expressing their frustration with a mix of humour and anger: