Sir Emyr Jones Parry's convention will report in October 2009
Members of the public are being asked to apply for positions on a panel looking at Welsh devolution's future.
The All Wales Convention will examine arguments for and against further powers for the Welsh assembly ahead of a possible referendum.
As well as the chair, former diplomat Sir Emyr Jones Parry, it will have 16 members, with four selected after an open application process.
The convention is due to report to the assembly government in October 2009.
The convention will be run by an executive committee comprised of four members nominated by the political parties, eight from key organisations and four members of the public.
The convention will hear evidence and gather information on whether the assembly should get more powers, before presenting a report to ministers.
Sir Emyr said the convention should be "open to all people, all parts of Wales and all arguments".
A referendum on full law-making powers for the assembly before 2011 is a key commitment of the Labour and Plaid Cymru coalition government.
Launching a website to promote the convention's work, First Minister Rhodri Morgan said it should reflect all aspects of modern Wales and "ensure that everyone's voice is heard during this important national debate."
Applications and nominations for membership of the committee must be submitted by Tuesday, 27 May.
Deputy First Minister Ieuan Wyn Jones said: "We are looking for applications from people in all walks of life - anyone who has an interest in guiding the direction of the convention and playing a part in moving Wales forward."