Mr Sarwar also announced that his party would introduce a new certification scheme awarded to businesses which do not use zero-hour contracts, pay the Scottish living wage and produce an emissions reduction plan or commit to net zero.
The latest election pledge, announced Sunday, would see companies awarded public contracts barred from signing staff up to zero-hour agreements.
Mr Sarwar said it would be part of an attempt to ensure Scotland's recovery from Covid-19 made employment fairer.
"Alongside the tragic death toll that this pandemic has caused we have taken an economic hit harder and deeper than the banking crisis," he said.
"We need to put a jobs recovery at the heart of our plan for a national recovery from the pandemic.
"But we need to make sure that our economic recovery is based on fairness and good work - we cannot go back to the inequalities and the broken economic model pre-Covid."
He said the current ‘Fair Work First’ rules over public procurement only preclude the ‘inappropriate’ use of zero-hours contracts – leaving the door open to zero-hours being used by companies benefiting from public procurement.As a result, Scottish Labour is committed to preventing any public sector procurement work going to companies that use zero-hours contracts.
He added: "We should bring an end to the use of zero-hours contracts by companies that benefit from public funds and establish a 'Better Business Scotland' certification scheme to promote good work principles.”