A veteran Scottish Labour MEP has called for the groundwork to be laid for a possible coalition between the party and the SNP at Holyrood.
David Martin acknowledged the prospect may seem "unthinkable" to many.
But he insisted there were increasing signs that the "real hate" between the two parties was lessening.
And he said moves towards finding more common ground should begin now in case neither party wins a majority at the next election in 2021.
SNP MEP Alyn Smith said Mr Martin's call was a "welcome intervention" - but a spokesman for Scottish Labour said it planned to replace the SNP as the next Scottish government rather than do a deal with it.
And the SNP claimed Labour "remains obsessed with attacking the SNP instead of standing up to the Tories".
Differences over independence
Mr Martin has been an MEP since 1984, making him the UK's longest-serving MEP and the second longest-serving in the whole European Parliament.
He voted against independence in the referendum in 2014, but said earlier this year that Brexit had left him unsure how he would vote in any future independence referendum.
Speaking to The Herald newspaper, he said it was time for Labour and the SNP to set aside their differences over independence.
He called on the two centre-left parties to instead focus on the common ground between them on issues such as health, education and, increasingly, tax.
And he urged Scottish politicians to become less tribal, arguing that "compromise is not a dirty word".
Mr Martin said: "We are far away from the next Holyrood elections but I think the groundwork should be being laid now for a potential SNP-Labour coalition that to many will seem unthinkable.
"There are signals, very weak signals, the real hate - and it was hate - between Labour and the SNP is beginning to weaken.
"I would not quite say there is a rapprochement but there is more possibility of co-operation and working together than there has been in a long time. Being on the same side in the Brexit referendum has helped that."
Welcoming Mr Martin's remarks, SNP MEP Alyn Smith said he agreed that a coalition with Labour was not unthinkable, pointing out that the two parties currently form the coalition that runs the City of Edinburgh Council.
Former Labour MSP and minister Malcolm Chisholm also signalled his support for the idea, posting "I like this" on Twitter.
But a Scottish Labour spokesman said: "We do not support a deal, pact or coalition with the SNP - we plan on replacing the Nationalists as the next Scottish government."
And an SNP spokesman said: "While we are always open to co-operating with other parties based on shared values, Labour remain obsessed with attacking the SNP instead of standing up to the Tories and their disastrous plans for an extreme Brexit."
Scottish Conservative deputy leader Jackson Carlaw said Mr Martin's comments were "further proof that Labour's main objective seems to be to conspire alongside the nationalists to fight the will of the Scottish people".
He added: "We all know what the consequence of that would be for Scotland's place in the UK."
The Scottish government was formed by a coalition between Labour and the Liberal Democrats between 1999 and 2007.
The SNP then formed a minority government in 2007, which largely relied on Tory support to pass its budgets, before winning a majority four years later.
The party returned to minority government last year, and relied on support from the Scottish Greens to pass its most recent budget.