Labour and Plaid Cymru AMs and MPs are discussing how a convention on more power for the Welsh assembly will work.
Sir Emyr Jones Parry is the chair of the convention
A referendum on further law-making powers for the assembly before 2011 is a key commitment of the Labour and Plaid coalition government.
The One Wales agreement drawn up by the two parties in their coalition deal calls for a convention in order to assess whether a referendum can be won.
The steering group will also decide the membership of the convention.
Sir Emyr Jones Parry, the former UK ambassador to the United Nations, has already been announced as the chair of the convention, whose steering group is examining how it will operate.
Currently, in order to make laws in some devolved areas, the assembly government has first to seek extra powers from the UK government in Westminster.
If a referendum were won, Wales could pass its own laws in all devolved areas like health, education and transport. That would mean it would work like the Scottish Parliament without further reference to Westminster.
'Prejudices and posturing'
Wrexham Labour AM Lesley Griffiths said the politicians involved had a "big responsibility" and needed to "set the right tone" for the convention's work.
She said the steering group's members came "from both sides of the devolution argument" and it was "crucial that those prejudices and posturing are left outside the door of the meeting room".
All four main political parties in the assembly are broadly in favour of more powers, but the Welsh Secretary Peter Hain has said he is sceptical about whether the public will vote for them before 2011.
Sir Emyr is expected to present his report to First Minister Rhodri Morgan and Deputy First Minister Ieuan Wyn Jones by mid-2009.