DAVID Cameron told people to stop “griping” as the bitter row over delays to flagship track improvements escalated.

Answering questions in the Commons, the Prime Minister turned on critics of the decision to “pause” the planned electrification of the TransPennine route, from York to Manchester.

The project has been described as “vital” for economic growth by Network Rail and funding was pledged as far back as 2011.

Meanwhile, Teesside MPs have also raised the alarm over the knock-on effect on separate plans to electrify the line between Northallerton and Middlesbrough.

During Prime Minister’s questions, Mr Cameron was told of “huge concern across the North” and urged to explain if he knew about the looming delay before campaigning on the promise of electrification at the general election.

Network Rail minutes have revealed that, as recently as March, the organisation responsible for track upgrades was planning a post-election announcement with ministers.

But Mr Cameron told MPs: “No, I was told about this after the election as we’ve set out before.”

And he added: “The point now is that we need to do everything we can to get to the bottom of the overspending and the engineering difficulties.

“Frankly, we have committed vast sums of money, a £38bn programme, to rail and - instead of griping and raising these grievances - the whole House should get behind this programme and make sure we get on with it.”

Although electrification would cut only around ten minutes off journey times across the Pennines, it also delivers ‘greener’ more comfortable services.

Now there is no guarantee it will be completed by 2024 – let alone any further upgrades – with electrification of the London to Swansea route the “priority”.

The department for transport has insisted it was kept in the dark about Network Rail’s problems until after polling day, despite having “direct oversight”.

Meanwhile, one senior rail executive told the BBC that Network Rail's plans in the North were a “standing joke” – and that further delays to key projects are expected.

The TransPennine route is the only major new cross-Northern rail scheme in the pipeline and is, therefore, seen as crucial to the so-called ‘Northern Powerhouse’ project.

Last month, David Cameron told MPs that the Northern Powerhouse “means linking the great cities of the North of England and making the most of them”.

Transport Secretary Patrick McLoughlin blamed rising costs and delays for the decision – caused by problems in the supply chain for signals and difficulties gaining planning permission.

A report will be carried out by Sir Peter Hendy, who has been parachuted into Network Rail to sort out the crisis.