Mark Drakeford criticised a “Mystic Meg”-style motion on next week’s UK budget.

Wales’ finance secretary responded to a Plaid Cymru debate held in the Senedd exactly a week before the new UK Government’s first budget announcement on October 30.

He said: “I lost count of the number of times in which Plaid Cymru members used the word ‘demand’ as though the volume of our voice mattered more than the quality of our argument.

“And, alongside that student union approach to debating, you have a sort of Mystic Meg approach to the construction of propositions for debate.

“We don’t know, and actually you don’t know, what is going to be in the budget next week – yet your motion tells us already that it’s let Wales down.”

But Heledd Fychan, Plaid's shadow finance secretary, stressed that the premise of the debate was to try to influence rather than predict the budget.

Her motion called for £4bn from HS2, devolution of the Crown Estate, new funding formula for Wales, U-turn on the winter fuel allowance, and an end to the two-child benefit cap.

She criticised the Welsh Government for 'watering down' previous demands and seeking to delete all five calls from the motion.

Raising the example of HS2, she said the Welsh Government is now 'requesting a commitment to further discussion' rather than reiterating previous calls for £4bn.

Peter Fox agreed with the much of Plaid Cymru motion, aside from the devolution of the Crown Estate which he argued would not be in the best interests of Wales.

The Conservatives’ shadow finance secretary said next week’s 'long-awaited' budget will follow in the 'incredibly disappointing' footsteps of the first 100 days of Labour.

Mr Fox raised a warning from the older people’s commissioner for Wales that cutting universal winter fuel payments could lead to 4,000 excess deaths.

The Senedd voted against Plaid Cymru’s motion and the Conservative amendment.

The Welsh Government’s “delete-all” amendment was also rejected, 28-27, with David Rees, the deputy speaker or Dirprwy Lywydd, using his casting vote in line with convention.