Appeal over electrifying rail line to Swansea
The assembly government is to urge the Department for Transport to reconsider its decision not to electrify the rail line as far as Swansea.
The £1bn electrification of the Great Western line between London and Cardiff was confirmed by the UK government on Tuesday.
Deputy First Minister Ieuan Wyn Jones said he would ask for a rethink.
He said there was still a "robust business case" for electrification to Swansea.
"We think that it's imperative because we want the economic benefits to flow not just to the south east but also south west Wales," said Mr Jones.
"As Swansea is one of our major cities, I think it's entitled to see the major investment coming to it through electrification."
The UK government said it had found "no evidence of a pattern of demand" and trains will switch to diesel power between Cardiff and Swansea from 2017.
However, electrifying the south Wales valleys commuter lines remains a future possibility.
There has been mixed reaction to Tuesday's announcement.
Cardiff council's leader Rodney Berman applauded the decision: "It knocks about 20 minutes off the journey time which is going to make Cardiff more attractive to businesses coming to locate.
"They will look at that journey time and think it's closer to London and Heathrow and that's good for the economy of south Wales.
"I think we've got to remember Swansea is going to benefit from this as well.
'Kick in the teeth'
"We're getting an awful lot of doom and gloom, particularly for political reasons, but we're forgetting this is beneficial to both cities."
But Andrew Davies, Labour assembly member for Swansea West, said it was "disappointing".
"Once again Swansea and west Wales is being regarded as second class.
"This is a kick in the teeth for people and yet another broken promise by the Conservative and Liberal Democrat coalition government.
"It would be far more cost effective to do this all at the same time."
Martin Evans, of the Transport Research Centre at the University of Glamorgan, said in the future the decision not to electrify as far as Swansea may be considered "perverse".
He said: "Prosperity declines the further away you get from London.
"Swansea is already far away from London and Europe.
"I think the problem will be perception because Swansea is looking like it's somewhere beyond the end of the line."
In a statement to MPs, Transport Secretary Philip Hammond said he had looked carefully at the arguments in favour of electrifying the line as far as Swansea.
But with no evidence of a pattern of demand that would lead to an increase of the one service an hour between London and Swansea, Mr Hammond said there was not a viable business case for electrification of the main line between Cardiff and Swansea.