Newly-released UK government papers have revealed Prime Minister Harold Wilson's difficulties in attempting to set up a Welsh assembly in the 1970s.
Wilson faced opposition to devolution from within his own party
Documents at the National Archives show widespread discontent within his own Labour cabinet over plans to set up Welsh and Scottish assemblies in 1975.
The previously unseen papers show that there was substantial unease within the Labour Party over plans for devolution.
The plans survived, but were rejected in Wales in the 1979 referendum.
Previously unseen documents released under the 30 year rule show the full extent of Harold Wilson's difficulties over the earlier attempt to introduce devolution.
The Welsh assembly was created following a 1997 referendum
Doubts were expressed by senior figures including the then-chancellor, Denis Healey and by a number of backbench Labour MPs.
Wilson's government also had a small parliamentary majority.
According to the papers, Mr Wilson was warned by Bernard Donoghue, a senior adviser, that the government's entire devolution plans could collapse.
However, the plans survived, partly because the Wilson government feared the rise of Scottish nationalism and also due to the actions of pro-devolution cabinet ministers including Welsh Secretary John Morris to maintain the manifesto commitment for a referendum.
Proposals for Welsh and Scottish assemblies failed in referendums eventually held in 1979.
The existing Welsh assembly in Cardiff Bay was created in 1999 after a devolution referendum two years earlier.