Chief executives in leading companies earn 183 times that of workers with an average of almost £5 million a year, a study has revealed.
The 10 highest-paid CEOs were paid over £156 million between them last year, research by think tank High Pay Centre found.
The average pay in FTSE 100 companies jumped to £4.9 million last year compared with £4.1 million in 2010.
Only a quarter of the FTSE 100 firms are accredited to the Living Wage Foundation for paying the living wage, the report added.
The report said changes to regulations in 2013 so that UK-listed companies have to publish pay details of their lead executive appear to have had virtually no effect in curbing "excessive" executive pay.
"It seems highly unlikely that the gap between CEOs and other workers will close in the foreseeable future," said the report.
TUC general secretary Frances O'Grady said the findings showed that "inequality is reaching stratospheric levels".