Trade union Unite has called for the government to explore whether money can be clawed back from Carillion's directors and shareholders to plug its pension.
Another trade union, the GMB, has also criticised the "broken system" which allowed Carillion to keep winning Government contracts while hiding a huge deficit.
Carillion had 13 final salary schemes in the UK with more than 28,500 members, and a deficit of £587m at the end of July, according to the company's results.
After unsuccessful talks with its lenders and the UK government, Carillion went into compulsory liquidation earlier this month.
The defined benefit (DB) pension schemes of Carillion, one of the UK government's biggest contractors, are all either in the retirement fund of last resort, the Pension Protection Fund (PPF), or will soon enter it.
Gail Cartmail, Unite’s assistant general secretary, said the scale of the deficit was "astronomical".
She said: "It is disgraceful that the company continued to pay shareholders dividends and to pay bonuses to its senior staff, while the pension black hole was allowed to spiral out of control.
"Members of Carillion’s pension schemes will pay for the greed of the directors and the shareholders for the rest of their lives, with vastly reduced retirement incomes."
She added that Richard Howson, Carillion's former chief executive, received £6m in pay and perks in the five years before resigning in July 2017, when Carillion was first forced to issue a profit warning. He also received 40 per cent of his salary as pension contributions.
Despite his resignation, Mr Howson continued to be paid a basic wage of £55,000 a month, Unite added.
Ms Cartmail added: "Every legal avenue needs to be explored to discover if money can be reclaimed from directors and shareholders and if those responsible can be prosecuted.
"It is outrageous that those responsible, who were lining their pockets while Carillion collapsed, could escape scot-free.
"The Carillion crisis demonstrates once again that existing pension laws are far too weak. The actions of The Pension Regulator need to be urgently reviewed and if necessary its powers strengthened.
"Yet again the government has been caught sleeping on the job and its processes have been found not fit for purpose. New laws must be introduced which mean that bosses who benefit at the expense of pension members are suitably punished."
The unions’ remarks come after the work and pensions select committee published a letter from Robin Ellison, chairman of trustees of six of Carillion's pension schemes, detailing the fund’s deficit calculations and negotiations with the company and The Pensions Regulator (TPR).
The regulator has, in the meantime, denied any negligence over Carillion’s pension funds.
Rehana Azam, GMB’s national secretary, said: "Thousands of Carillion workers still don’t know what will happen to them as their pay, terms and conditions hang in the balance - and worse, the prospect of their pensions being raided.