The Government has rejected calls for a formal review of the worst-performing rail franchise in the country.

Thousands of people had signed a petition calling for the Department for Transport (DfT) to address the "unacceptable level of service" provided by Southern, which operates lines in south London and Surrey.

MPs last week called for Govia Thameslink Railway (GTR), which owns Southern, to be stripped of its franchise amid mounting frustration over punctuality, cancelled trains and overcrowding.

The petition, signed by 12,466 people before it closed on May 28, read: "This company's punctuality and level of customer service is severely lacking and is damaging the lives and economy of those served by this operator.

"We are calling for a formal review of this operator."

But the Government, in its response to the petition this week, said Govia had plans to "reverse decades of under-investment on the rail network" and said ministers anticipated a return "to the performance that all passengers deserve" by 2018.

It added: "A further review into GTR will not address the challenges that their plans intend to overcome."

FROM MAY: Hundreds of trains cancelled as Southern conductors stage second strike

FROM MAY: Rail network punctuality drops to worst level in almost a decade, figures show

A survey by regulators at the Office of Rail and Road found that GTR, which also runs Thameslink trains and the Gatwick Express service, had the worst punctuality in the country in the year to March 2016.

Just one in five Southern trains arrived on time in the year to March 2016.

The rail company has repeatedly come under fire in recent months over punctuality issues, levels of customer service and understaffing.

From June 2: MPs want rail operator to be stripped of its franchise

From June 6: Union hits out at Southern Railway over 'dirty tricks' on staffing levels

Transport for London is due to take over all suburban routes in the capital, including those operated by Govia companies Southern and Thameslink, by 2021.

Chris Philp, Croydon South MP, and Tom Brake, MP for Carshalton and Wallington, last week called for the company to be stripped of its franchises at the “earliest possibility” earlier this month.

But Government spokesman said: “The challenges of this part of the network are not new. The industry and Government are addressing the longstanding, historic problems, including driver shortages, rolling stock and network capacity.

“By 2018 we expect to return the network to the performance that all passengers deserve, and we will do it with increased capacity, renewed facilities and robust, durable infrastructure.”

A so-called "remedial plan" was agreed between the Government and GTR last year.

It included obligation that the operator recruit and train more drivers, improve reliability, and provide better customer information.

But union RMT claimed the agreement allowed GTR to increase the number of cancellations without penalty.

Your Local Guardian:

Tom Brake is among MPs who have called for Govia to be stripped of its franchises

GTR this week acknowledged the poor quality of service on its Southern lines.

A GTR spokesperson said: "Whilst we wouldn't offer an opinion on the government's response, we can reiterate that we fully acknowledge that our service provision isn't good at the moment.

“There are a number of reasons for this, most of which are not within our control, some of which are, and we assure everyone that we are doing everything we can, together with Network Rail to improve punctuality and reliability on our network."

Click here view the petition and the government’s response in full.