Unite chief Len McCluskey will call for urgent action to boost the economy as his campaign for the union's leadership comes to Scotland.
Mr McCluskey, who faces a challenge to his post as general secretary from rival Gerard Coyne, will tell a rally in Glasgow a ''shot-in-the-arm'' is needed to protect workers' rights.
The leader of the country's biggest trade union will back a public investment plan for the offshore industry similar to the bailing-out of the banks after the financial crash in 2008.
He will also call for the devolution of employment law to Holyrood and for the historic debts of Scottish councils to the UK Treasury to be written off.
Speaking ahead of the Saturday event, Mr McCluskey said: ''From listening to our members, I know all too well that they want much more done to build this economy for tomorrow.
''That is why I am here to call for a co-ordinated shot-in-the-arm for the workers of this country.
''That must begin with urgent investment in the vital offshore sector to protect the tremendous wealth of skills and unleash the potential in this sector.
''So, too, is it high time that Westminster addressed the ludicrous situation whereby Scottish local authorities are saddled with the debts of long-gone days.
''Scotland's schools and communities are far more needy and deserving of this cash than a Treasury bank account - it is only right that they get it.
''I also want to urge Holyrood to play its part. I am determined that Unite will do everything in its power to fight against a Tory Brexit for the bankers and for one that supports working people.
''I urge the Scottish Government to play its part and demand it has the powers to defend the human and employment rights of the people of this country.''