A full referendum to give the Welsh Assembly Government full law-making powers would produce a no vote if called now, the first minister says.
Rhodri Morgan and Welsh Secretary Peter Hain both said that they would not win if a referendum was called in the current climate.
"Rhodri and I and Welsh Labour are not in the business of calling referendums we are going to lose," said Mr Hain.
Mr Morgan said:"You have to wait for the consensus."
Their comments came after the publication by the UK government on Thursday of the Government of Wales Bill for the biggest transfer of power from Westminster to Wales since 1999 when the assembly was set up.
The Bill is expected to transform the ability of the assembly to pass new laws, and will see significant changes to the electoral system.
Rhodri Morgan and Peter Hain don't want to call a referendum yet
The legislation will mean the assembly will not have to compete with UK Government departments for a slot in the Queen's speech at Westminster and the decision-making process should be much quicker.
It also paves the way for full law-making powers to be transferred to Cardiff Bay, but only after a referendum - which neither Mr Hain or Mr Morgan envisage happening in the near future.
The Bill has been criticised for relying on the goodwill of the UK government to allow the assembly to pass measures.
But Mr Hain defended it by saying if a hostile "John Redwood-style Government" in Parliament tried to frustrate the assembly's wishes, it would create an "overwhelming case" for a referendum.
With more powers, but no increase in AMs, as some had called for, Mr Morgan said members would have to work harder under the new measures being proposed.
He said parties now had to think how best to use the powers in the Bill, which is expected to have its second reading soon after Christmas.
"Their manifestos will be a bit more exciting than manifestos have been able to be in the first two assembly elections," he said.
Opposition parties have criticised the bill, with both Plaid Cymru and the Welsh Liberal Democrats describing it as "timid" and the Welsh Conservatives saying it would be "a rigging of the electoral system to suit the Labour party".
But despite the criticisms, assembly presiding officer Lord Dafydd Elis-Thomas, welcomed the provision to clear up the distinction between the assembly and the Welsh Assembly Government.
Assembly ministers will become royal appointees under the bill, like their Westminster and Holyrood counterparts.
"The confusion between assembly and government which has bedevilled Welsh politics since 1999 will finally be brought to an end and we will have legal clarity," he said.