Britain's top business bosses are reportedly sharing a combined pension pot worth almost £900 million.
Unions claim that directors at the UK's biggest companies have final salary pension schemes valued at £891 million, allowing the majority to retire at 60 with a pension of £3 million.
The annual analysis of boardroom pensions from the Trades Union Congress (TUC), drawn from information supplied in annual reports of 102 companies, shows that the average employee pension is 15 per cent smaller in comparison with last year's data.
Earlier this year a separate survey from the Joseph Rowntree Foundation (JRF) warned that the gap between rich and poor in the UK was at its highest for 40 years.
The JRF found that wealthier households had become "disproportionately" better off compared with the rest of society.
Today's TUC report claims that at least one company director is expected to be awarded a pension of £21 million, while five bosses have pension pots worth at least £12 million.
"Britain's boardroom bonanza does not stop on retirement. Too many top directors have gone on closing or cutting schemes for their workforce, while keeping gold-plated pensions for themselves," TUC general secretary Brendan Barber said.
"Even if top directors were in the same scheme as their workforce they would still get big pensions because their pay is so much greater than those of the staff they employ. But this is not enough for many top bosses; they need to have a guaranteed extra on top."
According to the TUC data 79 per cent of companies offer final salary pension schemes to their directors, despite two-thirds of firms closing the same schemes to new staff, while pensions for bosses are said to grow twice as fast as the most common rate for workers.
"Top executive pay has already created a new group of the super-rich who float free from the rest of society. This report shows that this does not stop with their retirement," Mr Barber added.
Commenting on the TUC's research, the Confederation of British Industry's (CBI) deputy director general John Cridland said: "These days, successful company directors are in demand around the world, so while big number salaries and pensions might feel uncomfortable or unfair to some, cutting ourselves off from the global talent market or taxing high fliers out of existence would harm the UK's economy at no benefit to ordinary workers.
"Top execs have often served companies for many years and like any longstanding employee, are more likely to be in final salary pension schemes with earlier retirement dates and will have built up sizeable pension pots too."