Kenny MacAskill, who served as justice secretary for seven years, argued that a possible deal between the two rival parties was “common sense”.
His call comes after veteran Labour MEP David Martin suggested the groundwork should be laid for a possible coalition between the two parties in the Scottish Parliament.
Now Mr MacAskill has said: “I agree with David Martin.”
The former SNP MSP told the Sunday Herald newspaper: “Such coalitions will have to be considered. It is long overdue. The hatred is deep and the divide, as in Ireland, is over the constitution, not necessarily over policies.”
He added that if Labour and the SNP do not work together, the Tories would be beneficiaries, saying that the “only winners are going to be the forces of reaction and the right”.
Mr MacAskill cited the governing Labour-SNP coalition at Edinburgh City Council as showing that the two parties could work together.
“They have done it in Edinburgh. We’re now into a second SNP-Labour coalition,” he said.
Last month Mr Martin pointed to the united front of the Labour Welsh Government and the SNP administration in Edinburgh on Brexit as an example of joint working, as he suggested moves to recognise common ground were necessary in case the 2021 Holyrood elections fail to give either party a majority.
The MEP said then: ‘’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 cooperation and working together than there has been in a long time. Being on the same side in the Brexit referendum has helped that.”