Campaigners have long called for a Welsh inquiry- something Plaid Cymru pledged to do in its manifesto.
Reforms that were postponed in 2024 estimated 800,000 homes could see cuts in council tax bills.
Plaid Cymru's leader makes pledge ahead of talks with Andy Burnham, who wants more devolution to councils.
Sarah Cooper-Lesadd, who defected to Plaid Cymru, says she is "not surprised" by new allegations.
The Senedd was told the government could achieve its environmental aims without the cost of creating the park.
The Plaid Cymru-led administration had failed to pass its spending plans during the summer.
Rhun ap Iorwerth says he stands "shoulder to shoulder with the Jewish communities in Wales".
Liz Saville Roberts says Andy Burnham should not wait for general election to show "leadership" on EU.
Rhun ap Iorwerth demands the UK government devolve policing, justice and welfare powers to Cardiff Bay.
