Taxpayers in Wales have been "let down" by Welsh Government's "mismanagement" which saw them lose out on millions during Covid, it has been claimed.
The money was lost by the government due to "poor account management" according to a Senedd Committee.
The unspent money of more than £150m had to be given back to the UK Government in 2021 after a request to carry the funds forward were rejected by the Treasury, leading to the Welsh Government being accused of "poor record keeping" and "mismanagement".
The TaxPayers Alliance said the losses, which also saw £37.2m lost to "fraud and errors", "can't be excused" and called for am inquiry into the government's handling of the covid crisis in Wales.
Joe Ventre, said: "Welsh taxpayers have been let down by oversight and mismanagement.
"The pandemic understandably meant that funds had to be provided quickly, but the loss of such large sums can't be excused.
"A swift, efficient inquiry into the Welsh government's handling of the covid crisis would help hold politicians to account."
It comes after a report was published on Monday by the Senedd's Public Accounts and Public Administration Committee. It included issues regarding Welsh Government spending, staff management, and concerns of fraud.
As a result of the error, the exact amount Wales lost out on was £155.5 million.
The committee highlighted the "significant funding" that was lost for the people of Wales and raised the question as to why Mark Drakeford's government "waited so long to be told it could not do as it wished with the underspend."
The Welsh Government said the Chief Secretary to the Treasury had rejected its request to carry forward funds in excess of the Wales Reserve limit, according to PAPAC.
The Wales Reserve was set up for Welsh Government to deposit any money which can be used to fund future spending and is held by the UK Government.
A Welsh Government spokesperson said: "The Finance Minister has made clear that the actions of the UK Treasury on this issue were wholly unacceptable.
"The UK Government refused a switch between revenue and capital budgets, a process which has been agreed many times before.
"Our underspends during the exceptional 2020-21 financial year were very significantly below those of UK Government departments and our focus on achieving value for money meant we didn't have the scandals of PPE contracts as we saw in England."
The Committee gave a scathing assessment of its actions accusing it of "poor record keeping" which has "cost the people of Wales".
Mark Isherwood, a Conservative Member of the Senedd for North Wales, and Chairman of PAPAC said: "It is one of many examples where poor record keeping and mismanagement of public accounts has cost the people of Wales.
"This money could have been used to fund essential services and it is especially frustrating now when there are such pressures on public funding."
What else did the committee find?
The inquiry also drew attention to "serious concerns" around senior staff management and the level of fraud and error in the COVID-19 business grants scheme.
A payment of £80,519 made to the former Permanent Secretary on her departure is one of a number of issues regarding the documentation of decision making and record keeping by the Welsh Government.
Poor record-keeping about how important decisions were taken prevented the committee from fully scrutinising the payment.
The committee also added that Welsh Government did not give enough evidence to justify the payment made on her departure.
Regarding the issue of fraud in the COVID-19 business grants scheme, the Welsh Government accepted there were "low levels of fraud and error."