New charges on internal flights and lorries would pay for a North-South high-speed rail link that could reduce journey times to Bradford, the Liberal Democrats will announce tomorrow.

Launching new transport policies to create a zero carbon transport system by 2050 the party promised to ensure the high-speed link, previously shelved by the Government, would get the go-ahead.

The multi-billion-pound improvements would be paid for through introducing a road toll for freight and charges on internal flights.

The 105-page document said the high-speed line would be "the best European standards to replace internal flights."

It reads: "Any new line would head north to serve Birmingham with one branch, in the first phase thereafter to Manchester and another to Leeds."

And the Lib Dems say they would increase capacity, new signalling and platform extensions on the West Yorkshire network to relieve peak-time overcrowding.

Furthermore the Colne to Skipton line would re-open, a metro system in Leeds would be introduced and a "facelift" for the York to Harrogate line carried out.

Shadow Transport Secretary Susan Kramer said: "Without substantial new investment, we will not have the 21st century rail network that our children and grandchildren need.

"We must modernise our transport infrastructure, or serious economic consequences will follow in the future."