Former first minister Henry McLeish has called on Scottish Labour to cut its ties with London, arguing that an independent party north of the border is now "essential".
Mr McLeish said UK Labour is facing "a summer of discontent and bitter infighting" with the leadership contest between Jeremy Corbyn and Owen Smith.
He argued the growing divisions within the party have left it "nowhere" in the debate over the UK's departure from the European Union (EU).
Mr Corbyn - who is the odds-on favourite to win the leadership contest due to conclude in September - is "not the answer to Labour's decline or long-term recovery", Mr McLeish insisted.
With Scotland facing the prospect of a second independence referendum as a result of the majority of Scots voting to remain in the EU, the former Labour first minister said the Scottish party must think beyond the leadership battle.
"In the short-term we will be wrapped up in the leadership campaign," he said.
"We need now to think beyond the next two months and prepare for every eventuality in Scotland and Britain as the political fall-out from June 23 continues and uncertainty deepens.
"Scotland could see Home Rule, a form of federalism, independence or some other, as yet unknown, four-nation constitutional solution.
"Regardless of the outcome, an Independent Labour Party (ILP) in Scotland is essential.
"The ILP imprint would send a powerful message of Scottish identity and politically-distinctive policies. This is the time for the Scottish party to act."
Leader Kezia Dugdale sought greater autonomy for the Scottish party last year while her deputy Alex Rowley advocated an independent party.