Secretary of state for Wales Stephen Crabb has said a deal over who will pay to electrify the valleys rail network will be ready in "a short number of months".

The valleys rail electrification is scheduled for completion between 2019 and 2024, but has been marred by a dispute that arose between the Welsh government and Westminster over who would pay for the scheme, the BBC reports.

Mr Crabb told Radio Wales' Sunday Supplement programme rail electrification is the "number one issue" for him.

He described the project, which is estimated to cost between £309 million and £463 million, as "probably the most knotty" problem between the two governments but insisted a solution could be found.

"It's something that I've been spending quite a bit of my summer working on," he declared.

The Welsh secretary said businesses in the south of Wales are keen to see the matter solved and they want the governments to work together to ensure progress is made.