Labour has been accused of 'torpedoing' plans to give the Welsh Government new financial powers. But in return Labour says those plans are politically-motivated and risk undermining Wales' place in the United Kingdom.
The accusations were made in the House of Commons during a special meeting of the Welsh Grand Committee to debate the draft Wales Bill. This is the legislation which would transfer control over some taxes including income tax (following a referendum) as recommended by the Silk Commission.
Shadow Welsh Secretary Owen Smith described the proposals as a 'trap' and a means of cutting funding to Wales.
He said Labour had 'never sought to devolve income tax-varying powers and warned that such a move risks 'undermining the union' by limiting the 'ability to pool risk and share rewards between the peoples and regions and nations of Britain.'
In response, Conservative MP Glyn Davies accused his Labour opponents of 'torpedoing' the plans as recommended by the Silk Commission. He took to Twitter to underline his point.
The difference of opinion during today's session of the Welsh Grand committee was sharply on party lines. On the one side of the committee room MPs hailed latest figures as proof that UK Government action is helping turn around the economy in Wales.
On the other side, mostly Labour MPs said cuts in spending are hitting Wales disproportionately and dismissed claims of growth in the economy as being based on increasing personal debt and inflated house prices.
But Welsh Secretary David Jones told the Welsh Grand committee that 'people in Wales have seen their earnings increase by 4.4% in 2013 which is an increase of twice that of the UK as a whole and more than twice that of inflation.
Welsh MPs are set to clash over the UK Government's spending in Wales. In a day-long debate in the House of Commons they'll discuss the impact of the Chancellor's Autumn Statement on the Welsh economy.
Former Welsh Secretary Cheryl Gillan says the First Minister of Wales should face annual questioning by Members of Parliament. She said giving MPs a chance to scrutinise the Welsh Government's plans in devolved areas like health and education would strengthen devolution.
She told a House of Lords committee suggesting that MPs and AMs could meet 'under the auspices' of the Welsh Grand committee. But in an interview with me following her appearance in the Lords she's gone further by saying that it's the First Minister who should appear before the Welsh Grand.
Ms Gillan told me it follows a precedent which already exists: the Welsh Secretary is questioned by Assembly Members on the UK Government's plans in the aftermath of the Queen's Speech. You can see more in tonight's Sharp End 1035pm ITV Cymru Wales.
Labour MP Ann Clwyd says she'll raise complaints sent to her from patients in Welsh hospitals during today's Welsh Grand committee debate. The Cynon Valley MP has been appointed by the Prime Minister to investigate the way patients' concerns are dealt with by hospitals in England.
But she's previously said that many hundreds of the letters and emails she's received are from those who've had difficult experiences in hospitals here in Wales.