A row has flared between new Welsh Secretary Cheryl Gillan and her Labour predecessor over preparations for the assembly referendum.
Mrs Gillan says she is "shocked" by a lack of progress, but Peter Hain accused her of "spreading smears" and talking "pure rubbish on stilts".
He responded angrily to her comments on her first visit to Wales in the post.
She also met Welsh Liberal Democrat leader Kirsty Williams, whose party are in coalition with Tories at a UK level.
Plaid Cymru, who are in coalition with Labour in Cardiff Bay, responded to that meeting by accusing Kirsty Williams of getting too close to Mrs Gillan and issued "an open invitation" to left-leaning Lib Dems to join them.
Ms Williams pointed out that while Tories and Lib Dems are in the UK government together, that is not the case in Wales.
She said the meeting was held "so that we can understand each other's priorities and we can make sure that the actions taken by the new government in London serve Wales well in the way that they haven't been served well for 13 years under the Labour government".
Meanwhile, Mrs Gillan stressed that her priorities were the economy and the referendum, which could result in more powers for the assembly.
But she said: "I was shocked when I opened the first items on my desk to find that the question on the referendum had not been progressed at all."
Mrs Gillan said she had discussed the referendum in a "very constructive" meeting with First Minister Carwyn Jones and she wanted to take the issue forward.
"I've always said the people of Wales should decide in the referendum as to whether further powers should go down to the assembly, but of course we still have to look at all the technical details because no work was done on it," she said.
Mrs Gillan, who also said she and her officials would no longer travel first class on trains, added: "I want a spirit of mutual trust and recognition and respect between the two institutions because I think the people of Wales expect their politicians to work together in the interests of Wales."
Mr Hain reacted strongly to Mrs Gillan's comments and said all necessary work to prepare for a referendum "was carried out immediately under my express instructions".
He said consultation on which question will be asked of voters would take 10 weeks, which could not have been done during the election campaign, and the assembly government was "perfectly aware of the timetable and are satisfied with the course of progress to date".
"This is totally dishonest and she knows it," said the Neath MP.
"Instead of spreading smears, she should be spending her first week in the job reintroducing the housing Legislative Competence Order which the Tories blocked, and reverse Tory opposition on £12m funding to ensure Welsh news on Channel Three [ITV]."
BBC Welsh affairs editor Vaughan Roderick said the presence of the Welsh Lib Dem leader at a photo-opportunity with Mrs Gillan and Nick Bourne, leader of the assembly Tory group, raised eyebrows among her opponents.
Plaid Cymru AM Leanne Wood, and Jonathan Edwards, the new Carmarthen East and Dinefwr MP, urged "left-leaning or disillusioned Liberal Democrat supporters in Wales to switch their allegiance".
They said many Lib Dems would have "cringed when witnessing the love-in between David Cameron and Nick Clegg" and claimed that the Welsh party's leader was "cosying up" to Mrs Gillan.
Ms Williams said: "I'm here to meet Cheryl... to understand [her] priorities in her new job and for her to hear what the priorities of the Liberal Democrats are.
"While Cheryl is right to say that we have a coalition in London, it's not a coalition for us here between the Liberal Democrats and the Conservatives in Cardiff.
"But we need to make sure that this new government works properly for Wales and I take that very seriously and I know Cheryl and Nick Bourne do too."
She said she was "very proud that for the first time in decades the Liberal Democrats are not just talking about the changes they want to make, we are actually going to implement them instead".