The MP, who ousted former Mayoral contender Zac Goldmsith in last December’s by-election, made her call after transport secretary Chris Grayling announced FirstGroup and MTR would take over the service from August.
Earlier this year Mr Grayling abandoned a joint TfL/Department for Transport framework which would have seen London government gain more control over its rail services.
The plans had been agreed between former Mayor Boris Johnson and Grayling’s predecessor Patrick McLoughlin, and the Transport Secretary has been accused of allowing personal and partisan considerations to affect his decision.
FirstGroup and MTR have pledged to provide thousands of new seats in both the evening and morning rush hours, as well as to invest in new trains and refurbish existing rolling stock.
Mrs Olney said she welcomed the promised improvements but remained “disappointed that the Secretary of State for Transport, purely for ideological reasons, has ruled out allowing the franchises for suburban rail being awarded by TfL so allowing the benefits of the London Overground to be extended to more people in London and on suburban train routes.”
She added: “London Overground services have a much higher performance service than other rail companies. Their service also includes staffing from first to last train every day, ensuring that stations are safe and accessible for everyone.”
“However, now that a decision has been made my primary objective is to ensure that each and every promise made by First MRT South Western Trains Limited on new trains and extra seats is fully kept.
“I will hold not hesitate to hold them account on every one of their pledges.”
