The public services union Unison is to brief MSPs this week on the bill which it describes as very disappointing, claiming it does too little to tackle low pay, zero hours contracts and sustainable procurement of food.
The bill will receive its stage one debate on Thursday. However, Unison is to tell MSPs that none of a list of 10 'asks' presented to ministers by a coalition of charities and civil society groups have been heeded.
"There is widespread disappointment that a bill which was originally due to be the Sustainable Procurement Bill ... largely is about 'business-friendly processes", the written briefing states.
"There are deep concerns that short term economic arguments will be prioritised with only lip service paid to sustainability."
The union also calls on the Scottish Government to take action against companies found to have blacklisted workers, and adds: "Much more must be done to stop tax-dodging companies winning public contracts. Are members on the side of the tax-dodgers? Or will you take action to tackle them?"
Charities and unions had called for the bill to include a requirement that public bodies tackle low pay by requiring all suppliers to pay the living wage. They had also called for action on blacklisting and tax-dodging, a focus on sustainable development and promotion of fair trade, employment standards and social benefit in purchasing decisions.
Unison Scottish organiser Dave Watson said a race to the bottom in procurement was a big concern for many charities. "Many of those involved in delivering services are really struggling," he said. "People are having to cut corners in order to win contracts. Unless procurement is sorted out, this difficulty is not going to go away. We need a more credible approach."
Nicola Sturgeon, cabinet secretary for infrastructure, investment and cities, responded to concerns about the bill in a letter to the Scottish Parliament's Infrastructure and Capital Investment Committee at the end of last year. She said making the payment of the Scottish Living Wage mandatory for those bidding for public contracts was "likely to be a breach of our obligations under wider EU legislation and treaty principles".
She added that public bodies would be able to take blacklisting and failure to pay tax into account when awarding contracts.
Meanwhile, measures requiring authorities to take into account innovation and social benefit would ensure spending decisions were sustainable, she said. "Sustainability is at the heart of Scotland's public procurement reform programme."