Wales should remain part of the UK but have its own “meaningful” government, the Welsh Liberal Democrats have said.
Jane Dodds, the party’s leader in Wales, will call for a “truly equal family of nations” at her party’s conference in Bournemouth later.
Ms Dodds, who backs stopping Brexit, won the Brecon and Radnorshire by-election last month.
UK leader Jo Swinson will ask Lib Dem members to back a policy of scrapping Brexit without another referendum when their conference begins.
Ms Swinson wants to revoke Article 50 – the formal process to leave the EU – without asking the public as the referendum got the UK “into a mess”.
Until now, the party’s policy has been to campaign for another referendum but Ms Swinson said the party’s anti-Brexit message should be “unequivocal” in any possible general election campaign.
Ms Dodds taking the Brecon and Radnorshire seat was Ms Swinson’s first by-election as UK Lib Dem leader.
She will take the stage in Bournemouth saying only the Lib Dems will support to keep Wales in both unions, the United Kingdom and the European Union.
Ms Dodds, though, will campaign for moving more powers away from Westminster, calling for a federal structure that gives “every part of the union a voice” backed up with “meaningful devolution”.
She will tell the conference she is a “proud Welsh woman and a staunch believer in devolution”.
“I want to see devolution not just to the nations and regions, but to local government as well – to bring power as close to the people as possible,” Ms Dodds will say.
“I am also proud to be British and European.
“All of these identities are what makes me who I am, and are rooted in my belief that there are things we do better together – in the same way as there are things we do better as part of the European Union or as part of the United Nations.”