Plaid Cymru is calling for Wales to be given the same powers of control as Scotland.
Transport, crown estate, justice and policing, energy, taxation and welfare are among the powers held by Scotland but currently unavailable to Wales.
Plaid Cymru leader Rhun ap Iorwerth and the party’s Westminster leader Liz Saville Roberts are set to ask for “a Wales Bill based on the premise of parity of powers with Scotland” when they meet with Welsh Secretary Jo Stevens.
Mr ap Iorwerth says “Wales deserves its fair share” and his party’s call for parity with Scotland is “about securing the powers needed to truly improve the lives of people who live here”.
The Plaid Cymru representatives will also press the case for scrapping the Barnett Formula and introducing a funding model which funds Wales according to need, not population.
Mr ap Iorwerth said: “Scotland has shown how these powers can be used to better serve the people.
“A devolved benefits system has shielded people in Scotland from some of the most brutal Westminster austerity, while the devolved Scottish Crown Estate directly invests in deprived coastal communities.
“If Scotland can do it, why not Wales?”
Ms Saville Roberts said it was time to deliver the biggest ever transfer of powers out of Westminster, adding: “Only with greater powers can we create a fairer future for our communities.”
Plaid Cymru state that Scotland has authority over rail infrastructure, whereas Wales does not control its own railways or receive equivalent funding for infrastructure.
Management of the Crown Estate was devolved to Scotland in 2017, which means that Scotland can maximise the potential of its resources, and revenue is returned to Edinburgh rather than Westminster, they add.
It says the Senedd has primary law making powers but the region comes under the legal jurisdiction of “England and Wales”.
Wales has no powers over welfare while Scotland has been able to make successful moves on anti-poverty, according to Plaid Cymru.
