ANAS Sarwar is set to argue that there should be a “legal duty of co-operation” between the Holyrood and Westminster governments.
According to the Daily Record, the leader of the Scottish Labour party will make the announcement at an event in London where he will take aim at the SNP and Tories for trying to benefit from “a political climate which seeks to maximise disagreements and disordered relationships”.
Sarwar will also reportedly look to slam Nicola Sturgeon’s announcement of an independence referendum next year and say that it is a distraction from “failures in government”.
And Sarwar has now proposed a “new legal duty of co-operation between the UK and Scottish governments" which he says would "ensure they work together where they can and not against each other”.
He said: "We are proposing new models of inter-government working designed to heal the bad relationship that exist.”
Sarwar has also criticised both governments for focussing on constitutional issues which he argued would not help alleviate poverty or inequality.
The SNP have been contacted for comment regarding Sarwar's pending announcement.
Meanwhile, Keir Starmer is set to make an announcement on how the UK Labour party would "make Brexit work".
The five-point plan will claim that a government under his leadership would not join a customs union with the EU, in maintaining the hard Brexit deal brokered by Boris Johnson.
Starmer will make the announcement as he looks to distance himself from his legacy as shadow Brexit secretary under Jeremy Corbyn and past support for a second referendum on EU membership.