At today's meeting of the Welsh Grand Committee in Westminster, Plaid Cymru MPs accused the Labour party of showing an astonishing lack of ambition for Wales as Shadow Secretary of State Owen Smith poured cold water on plans for the devolution of income tax powers.
Speaking during the afternoon session, Arfon MP Hywel Williams, claimed that Labour had revealed their true colours as the anti-devolution party in Wales, putting up roadblocks to progress on the transfer of vital job-creating powers to Wales.
He warned that the Silk Commission was now in danger of being derailed thanks to Labour's political point-scoring and that Owen Smith's comments undermined previous comments made by the Welsh Finance Minister Jane Hutt and Welsh First Minister Carwyn Jones.
Speaking after the debate, Mr Williams said:
"Today, Labour revealed their true colours as the anti-devolution party.
"Even the Prime Minister used PMQs to state that he is in favour of taking these further steps to secure the transfer of income tax powers to the National Assembly.
"It is a sad day when the Tories in London speak more warmly about Welsh devolution than the Labour party in Wales!
"The transfer of income tax powers was proposed by the cross-party Silk Commission, whose recommendations were unanimously welcomed. If the Labour party had such a problem with Wales gaining more fiscal responsibility and accountability then why not say so sooner?
"This is a clear case of cynical backtracking from a Labour Party, running scared of the increasing support for Scottish independence and the implications of Barnett reform for the Scottish bloc grant - namely a loss of millions.
"Labour would rather please their Better Together bosses than reform a grossly unfair funding formula which sees Wales losing out on £300-400m each year according to the independent Holtham Commission.
"When asked again whether Labour's 2015 manifesto would contain a pledge to secure a fair funding settlement for Wales, MPs present at the committee failed to answer.
"Plaid Cymru is fully committed to reforming the Barnett formula and the immediate implementation of Silk's recommendations. While one Labour MP claimed today that "concentration" on Wales is a bad thing - my party takes pride in doing just that."