Labour last week suffered its worst share of the Welsh vote since 1918.
Richard Wyn Jones, director of the Institute of Welsh Politics, told the Western Mail newspaper that the 32 percent share was comparable to the 30.8 percent figure Labour gained in Wales when the party was still a fledgling political force.
Dr Jones, who teaches at the University of Wales, Aberystwyth, said, “The Labour Party has dominated Welsh politics for the last four or five generations.
“But under Rhodri Morgan’s leadership the share of votes has now plunged to its lowest level since 1918.
“In a historical context it’s really bad and I’m surprised that, thus far, they haven’t cottoned on to the fact.”
He said it easily eclipsed the poor performance under Alun Michael’s leadership in the 1999 Welsh assembly elections – considered catastrophic at the time – and was even worse than the run of bad results in the 1980s against Margaret Thatcher’s Conservative government.
The election saw Labour slip from 29 to 26 AMs in the 60-seat assembly. This means they must reach a coalition deal, which could prove problematic.
The Lib Dems would be obvious partners. But they are in turmoil after winning only six seats – the same as last time.
Their Welsh leader Mike German had set a target of between seven and 11.
The Lib Dems’ Welsh education spokesman Peter Black has already said the party should “move on” from the poor showing at the ballot box with an early leadership election.