The GMB union singled out Robin Southwell, chief executive of Atkins, for criticism by taking out a full-page advert in The Independent newspaper this week. Southwell was pictured above the caption: "Who are the real wreckers?"
The advert said that every pound going into Atkins' profit was a pound less for nurses and hospitals, adding: "Robin Southwell, Atkins chief executive, is very happy. He was paid £361,000 in the last financial year."
GMB general secretary John Edmonds said PFI contractors were "privatisation pay pirates" and called on Tony Blair, the prime minister, to condemn company bosses who get rich from government contracts.
Edmonds said: "Public sector workers cannot be expected to exercise restraint when they see millions squandered on salary hikes for rich directors."
A survey carried out by the Independent Labour Research Department for the GMB found that the average salary for the highest-paid directors at 10 PFI contractors last year was £583,000.
Unions also protested on the Blackpool seafront outside the congress, holding placards that criticised Balfour Beatty, AWG and Atkins for their PFI profits.
Blair told the TUC that the government was addressing union concerns over the emergence of a two-tier workforce in private sector firms who take on public sector contracts.
The fear is that staff recruited after a contract is awarded will be given worse terms and conditions than those who transferred from the public sector.
Blair said: "We are introducing rules so that recruits enjoy broadly comparable pay and conditions as other local government employees transferred to the private sector."
He added that he had been assured that most staff in hospital PFI schemes were able to remain on the NHS' terms and conditions of service, which are more favourable than those in the private sector.
A spokesperson for Atkins denied that resources were being diverted from the NHS to provide profits for it and its consortium partners.