When Plaid Cymru unveiled proposals for their £500m infrastructure investment fund "Build for Wales" last week, Labour were right in the vanguard of attacking it.
"Completely unworkable" and "electioneering of the worst sort" were two of the choicer phrases issued by the party in response.
It's clear to me that though this plan is different to that floated in Scotland - before being sunk by the Treasury - "Build for Wales" would also, realistically, need a nod from the Treasury.
Plaid said last week that "discussions with the UK Treasury are underway to enable the establishment and operation of this entity to take place".
The response from the Treasury has a less positive ring to it: ""UK Government officials only engage with Welsh Assembly Government officials on Welsh Assembly Government business, they do not engage with individual political parties or individual party policies. No discussions with the Welsh Assembly Government officials have so far taken place on this issue."
However they confirmed that the "Assembly Government has sent a paper for future discussions but there have been no discussions about it yet".
So there were some nagging questions here. Labour had comprehensively rubbished the plan unveiled by Plaid.
This very short document that has just appeared online now adds to those questions. What it shows is that within the last couple of months, the Labour Finance Minister Jane Hutt personally signed off on putting a plan that Plaid say is the one they proposed last week - to the Treasury on the Assembly Government's behalf. The Treasury have confirmed, above, that they've received it.
Jane Hutt took the lobby briefing this morning. So did she believe then that the plan outlined by Plaid was "completely unworkable" and "blatant electioneering"? Or did she think it was worth exploring, until Plaid unveiled it as a manifesto policy last week?
Her response: that "as a responsible government, we have to look at every mechanism;" that "we have to make sure that we are opening up all lines of discussion and a whole number of policy areas as indeed I have done consistently over the past year with the Chief Sec to Treasury" and that "there are no doors that should be closed".
Labour say this morning there had been plenty of theoretical discussions amongst ministers and officials about future mechanisms for funding capital projects in Wales at a time when the money that's around to spend on big projects has been slashed. But those theoretical discussions were "a quantum leap" away from any any sort of plan, let alone the plan outlined as "Build for Wales"
They're adamant and remain adamant that the idea of bonds was never part of any discussion and that Plaid are conflating all sorts of 'what if' discussions to claim Labour support one particular plan - which they don't.
Plaid, on the contrary, insist that the very same plan had Labour backing until it became public and that far from being in a position to accuse others of "blatant electioneering" are guilty of just that themselves and then some.
Someone, somewhere no doubt has access to a paper trail that would tell us who is right. I don't.
The Liberal Democrat leader Kirsty Williams has just told journalists that Labour are now in a "real mess" over this and that Jane Hutt has questions to answer about why her party issued what she called a "devastating critique" of a policy that she was proactively pursuing inside the government.
Plaid have put out a statement:
"This is an exciting and innovative proposal which could make a significant contribution to the Welsh economy at a time the Welsh capital budget is facing cuts of 41%. The other option would be to sit back and do nothing. So far, no comparable ideas have been proposed in respect of how Wales can meet this challenge.
"Plaid would of course welcome the support of the other parties to enable the public sector in Wales to invest more in its infrastructure, and would look forward to co-operating with them after May the 5th in showing a united front to the Treasury in the interests of the people of Wales."