A Network Rail study has concluded against the electrification of the over-crowded and slow Leeds-Manchester transpennine rail route in a move described as a "hammer blow" to the already troubled Northern Powerhouse idea.

A report on the electrification project — the precursor of a wider improvement in high-speed travel linking the northern cities — is now on the desk of Transport Secretary Chris Grayling, The Times reports.

"We expect to spend around £3B on a rolling series of upgrades on this key route between Manchester, Leeds and York from Spring 2019. We are working with Network Rail and Transport for the North to determine the best way to achieve these major improvements for passengers," a statement from the Department of Transport said.

"Network Rail has established options for infrastructure works that could deliver these improved journeys and we are considering these before making further decisions later this year," it added.

However, Greater Manchester Mayor Andy Burnham reacted angrily. "If today‘s report is not true, the Government needs to make that clear immediately. Failure to do so will continue to erode trust in the whole concept of a Northern Powerhouse," he said.