Speaking last Monday at a PFI conference, Wing warned that unions could intervene to exclude major contractors from PFI deals unless they improve the treatment of their staff.
Under a government policy statement issued last October, trade unions are allowed to interview and vet shortlisted bidders for all PFI contracts and question them about employment practices.
Wing said Unison will use the rules allowing trade unions to vet shortlisted PFI bidders to weed out "bad" contractors.
Wing said: "Companies like Tarmac are in a timewarp. I hope their attitude will be very bad for their business. It's time they stopped and reflected on the changing climate of social partnership." Tarmac was unavailable for comment.
Unison intends to co-operate with other unions, including UCATT, to build a database of contractors bidding for PFI schemes. This would be used to give interview panels detailed information on a contractor's health and safety record, its record in industrial tribunals and its policy on trade union recognition.
Companies like Tarmac are in a timewarp. I hope their attitude will be very bad for their business
Malcolm Wing, Unison
Wing said Unison had already produced a briefing paper for union representatives providing detailed guidance on the questions to ask during vetting interviews.
He said: "We live in the real world and we will ensure our representatives [in consultation forums] are well prepared." Amanda McIntyre, a senior policy adviser with the CBI, who also spoke at the conference, said: "Obviously we don't want cowboy contractors, but you've got to be careful in deciding whether a company is complying with legislation now." She said that companies did improve procedures after disputes, so the fact that a company had fallen foul of health and safety legislation in the past did not mean that it did not have more stringent procedures now.
She said CBI members were nervous about trade union representatives leaking confidential information gained during interviews.
The former Treasury PFI taskforce member and conference chairman Tony Whitehead said he hoped the conference would lead to a greater understanding between unions and PFI bidders.
He said: "The policy statement needs to be used responsibly. Whether you approve of PFI or not, the government has made it clear it's here to stay." David Coats, a senior policy adviser with the TUC, said: "In principle, trade unions are opposed to PFI. Don't discount the rhetoric, but be aware that unions want to do what's best and practical for their members, and they'll be selling their members short if they fail to recognise the opportunity the statement offers." The London conference was organised by quarterly publication PFI Report.