A leading Welsh Liberal Democrat is to call for the party to reclaim the radical traditions of liberalism.
Kirsty Williams is appealing to the party to return to its Liberal roots
In a speech in Aberystwyth, Assembly Member Kirsty Williams will attack what she calls the "gloopy grey consensus" of the "Cardiff Bay bubble".
It is seen as a bid to regain momentum for the party following the collapse of the "rainbow coalition" this summer.
The Brecon and Radnorshire AM is seen as the most likely contender to follow Mike German as Welsh Lib Dem leader.
Ms Williams, her party's assembly spokesperson for enterprise, transport and education, will deliver her rallying call in a speech to the Institute of Welsh Politics in Aberystwyth later.
The Liberal Democrats held talks with other opposition parties about forming a coalition after May's Welsh assembly election.
Labour and Plaid Cymru agreed their own partnership for power based around the One Wales document.
The Lib Dems won six seats in the last three assembly elections.
Ms Williams is expected to hit out at the "rugby club blazer" culture, attack the Labour Party's "patrician smugness" and say Welsh politics has lost the excitement and drama generated by devolution.
Ms Williams will warn in her speech that people are "frustrated by the gloopy grey consensus that Welsh politics has become".
She will criticise "a closed system where the same people meet in the same rooms to discuss the same ideas - a system which doesn't embrace the radical or the alternative".
She will go on to appeal for the Lib Dems to become the "radical, cutting edge of Welsh politics".
She will also urge the party to become one of "principle with practical policies to improve life for the Welsh people - all based on Liberal ideals".