Sadiq Khan and transport secretary Grant Shapps held their first meeting yesterday, in which the devolution of commuter lines to Transport for London (TfL) was at the top of the agenda.

Shapps, who replaced Chris Grayling as transport secretary in Boris Johnson’s Cabinet overhaul, is understood to be more open to the idea of giving TfL control over key commuter lines than his predecessor, who was reluctant to hand power to a Labour mayor.

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A source close to Khan said there were “positive signs” that Shapps, whose constituency of Welwyn Hatfield in Hertfordshire was heavily affected by last May’s timetable chaos, would be prepared to grant TfL power to run commuter lines, such as routes from the Home Counties and Oxfordshire.

“Previous transport secretaries, while Sadiq has been mayor, have been seen to block this, possibly for political reasons,” they said.

They described the meeting as “positive and constructive”.

“Hopefully it laid the foundations of what we all want to see – improvements in transport for Londoners,” they added.

In May last year Shapps called for Govia Thameslink Railway (GTR) to be stripped of its franchise in the wake of the thousands of delays and cancellations caused by the timetable change.

At the time he tweeted support for London Overground taking over GTR’s Great Northern route, which runs through his constituency.

TfL and the mayor have argued that devolution would mean that train services in south and south eastern London could be nearly as frequent as the Tube. They say TfL would be able to prioritise investment where it was needed, resulting in an increase in capacity and reduced journey times.

At a July session of mayor’s question time Khan said Johnson was a “passionate advocate of devolution” and that such a policy would mean rail users would see the “high standard of service seen on London Overground and TfL Rail – increased frequency, fully staffed stations, fewer delays and accessibility improvements”.

Sean McKee, director of policy and public affairs at the London Chamber of Commerce and Industry, which supports rail devolution to TfL, said: “Right now there are significant question marks over punctuality and capacity of some mainline routes – which will only be exacerbated by London’s growing population over the coming years.

“We believe that bringing these lines into TfL control will benefit them in the same way it has benefitted the Overground network and TfL Rail. Better connected locations also have increased potential to boost house building rates and related local economic investment.

Read more: Majority of Londoners support TfL control over commuter rail services

“For all these reasons we call on the transport secretary to support further rail devolution for London.”

A DfT spokesperson said: “The secretary of state was pleased to discuss his key priorities for the Department for Transport with the mayor of London on Monday.”