Furious political leaders in the north of England - including Sheffield - have raised fears about the future of the 'Northern Powerhouse' after Government backs billions for trains in south.
Transport Secretary Chris Grayling has sparked anger by supporting a new £30 billion Crossrail 2 scheme in London and the south-east, days after a series of rail projects in Wales, the Midlands and the north were axed or downgraded.
In a joint statement, leaders in Sheffield Manchester, Liverpool, Leeds and Newcastle said Mr Grayling's statements had created "considerable uncertainty" and raised fears about the future of the Northern Powerhouse and the Government's aim of rebalancing the UK economy.
The statement said: "If the Government can't be trusted to stick to promises already given, then it is hard to have confidence that they will deliver longer-term agreements made to the north.
"The Government urgently needs to clarify its position on both short-term and long-term commitments to the north and confirm if it remains committed to the Northern Powerhouse and Transport for the North."
The political figures, including Sheffield City Council leader Julie Dore and Greater Manchester Mayor Andy Burnham said they will organise a summit for northern political and business leaders in late August, before the return of Parliament.
The statement said: "We call on the Government to return to working constructively with us to correct long-term imbalances in transport funding and to give the people of the north the rail services they deserve and have been promised."
Manchester City Council leader Sir Richard Leese, Leeds City Council leader Judith Blake, Liverpool City Region Mayor Steve Rotherham and Newcastle City Council deputy leader Joyce McCarty also backed the statement.
The Department for Transport (DfT) has insisted money for the north is not being cut, despite earlier pledges to electrify trans-Pennine rail lines to improve speed and capacity now being shelved.
Instead, new "bi-mode" trains which run on diesel and electricity are planned. Critics say electric trains are faster, cleaner and greener.