The Government is facing mounting pressure to devolve suburban rail routes into London after new polling revealed most passengers back the proposal.
Transport Secretary Chris Grayling has been accused of putting politics ahead of passengers when a leaked letter showed he opposed devolution to keep the network "out of the clutches" of a Labour mayor.
He later blocked a request by London Mayor Sadiq Khan to hand control of the Southeastern commuter route to City Hall and Transport for London (TfL), saying there was no need for a massive reorganisation.
But just 14% of commuters back his decision to keep the capital's commuter lines in control of train operating companies, according to the YouGov poll, while 58% of passengers said Transport for London (TfL) should have more control over the routes, the survey found.
The findings come after the All Party Parliamentary Group for London - a cross party group of MPs - wrote to the Prime Minister to "register our dismay" at Mr Grayling's decision and call for the TfL's devolution bid to be "urgently re-assessed".
The poll of 1,000 adults, which was commissioned by the Greater London Authority, found that 52% of passengers think Mr Grayling made the wrong decision.
Just 14% think he made the right choice, while 58% think TfL should have more control of commuter rail lines and only 5% think it should have less.
Mr Khan said: "The Government is failing commuters with a terrible service, constant delays and cancellations while fares are increasing every year.
"Commuters deserve to be able to get to work and back on a reliable train service.
"This polling clearly demonstrates that commuters want the Government to give control of commuter rail lines to TfL, so they can get the more frequent, reliable and affordable service that they deserve.
"Conservative MPs and councils are also calling on the Government to review the decision taken by Chris Grayling, the current Transport Secretary, who went back on the previous promise made by his predecessor Patrick McLoughlin.
"It's time for the Transport Secretary to stop burying his head in the sand and listen to what commuters want. This is much more important than party politics - it is about people's jobs, time with their family and quality of life."