The UK government has underfunded Welsh railways for a "long, long time", a transport expert has told MPs.

Prof Mark Barry of Cardiff University, who proposed the South Wales Metro Plans, said Wales' rail network has not had a "fair crack of the whip".

He said the valley lines in south Wales were probably the most "depreciated" community rail networks in the UK.

The UK government said, in a statement, it was "investing record amounts in Wales' railway infrastructure".

Prof Barry was appearing in front of the Welsh Affairs Committee.

"We need to be spending another £1bn pounds on transport infrastructure in south east Wales because it's been depreciated for 30 or 40 years," he said.

"The evidence is there - we know Welsh railways haven't had a fair crack of the whip in terms of UK government funding for a long, long time.

"To depreciate an asset, it underperforms. It costs more to run, it attracts less passengers and it requires more subsidies.

"Any business knows that if you depreciate your asset, it's not going to perform as well. There's a deficit to be made up."

"The valleys line network is probably the most depreciated community rail networks in the UK," he added.

"If you're not going to invest in it you should actually close it," Prof Barry said.

Image caption Prof Mark Barry: "If you're not going to invest in it you should actually close it"

A UK government spokeswoman responded: "Network Rail's budget for the rail network in Wales between 2019-2024 is over £1.5bn.

"This investment will build a bigger, better rail for Wales, delivering improved journeys for passengers on the most advanced new trains.

"We are looking at ways to deliver journey time savings for passengers, committing to a West Wales Parkway station that could save up to 22 minutes for passengers travelling from west Wales to Cardiff, delivering better connectivity for commuters across south-west Wales and increasing opportunities for the region.

"We have also committed £125m towards the upgrade of the valley lines as part of a wider contribution of £500m to the Cardiff Capital Region Investment Fund, to help drive growth and increase employment."