A former Labour MP, who later defected to the Social Democratic Party before joining Tony Blair's new Labour, has become a member of Plaid Cymru.
David Marquand was a Nottinghamshire MP in the 1960s and 70s but now lives near Cardiff, where he was born in 1934.
He told a fringe meeting at the Plaid Conference that he'd "been in more parties than the Prince of Wales".
He was speaking in favour of what he called a "progressive alliance" on the left of politics.
Sat next to him was Plaid Cymru AM Bethan Jenkins who said the party had taken no decisions.
Although she welcomed discussing the idea of an alliance, she argued that co-operation with Labour was difficult when Labour MPs hadn't even joined Plaid Cymru in voting for the Welsh Government's proposals to strengthen the powers of the Assembly.
Her fellow Plaid AM Adam Price sounded more positive about the idea, arguing that extraordinary times called for extraordinary measures.
In the Conference itself, Labour came under attack over the Welsh Government's refusal to back Plaid Cymru's call for Britain to remain in the European Single Market.
Plaid AM Rhun ap Iorwerth said the Welsh Government had to "commit more energy to fighting Wales' corner".
Plaid MP Hywel Williams directed his fire on the Conservatives at Westminster.
The conference will conclude tomorrow after Plaid Cymru leader Leanne Wood gives a keynote speech that's expected to stress her party's willingness to work with Labour in the Assembly, with or without a formal coalition.
She will also amplify Plaid's a message about what it sees as threat to Wales from a hard Brexit.