The pay of top company directors rose by 18 per cent last year, pushing an increasing number into the million pound salary bracket.
A pay study of 310 directors found that almost half earned more than £1 million, with eight receiving packages worth more than £5 million.
Incomes Data Services, which has been monitoring executive pay for the past 15 years, said it had never known so many people earn so much money.
The pay of directors in the leading companies in the UK increased by 18.1 per cent in the year to June at a time when wage settlements across the economy were running at 3-3.5 per cent, the report showed.
IDS said its research proved that boardroom pay continued to be "ratcheted upwards".
The pay of the most senior executive in the top 100 companies went over £2 million for the first time. Directors received more long- term incentive plan awards and exercised more share options than a year ago.
Steve Tatton, editor of the IDS Executive Compensation Review, said: "The continuing upward trend in executive remuneration may partly be due to improved business conditions, but it is also partly due to the widespread restructuring of incentive schemes that has taken place over the last two or three years.
"In particular, incentive scheme maximum payments have been steadily rising with the result that potential payments have got bigger."
TUC General Secretary Brendan Barber warned: "The sky high increases of top executive pay show no sign of slowing. While ordinary workers are happy to accept pay rises in the region of 3.5 per cent, the bosses of the UK's top companies are rewarding themselves with pay packets that are almost six times bigger.
"It's time for shareholders to pay more attention to the total amount paid out to directors and concern themselves more with the gulf opening up between top bosses' pay and that of the rest of the workforce."
And female executives are still getting paid less than their male colleagues, according to a separate report.
Despite more women reaching the top rung of the corporate ladder they still earn, on average, almost 25 per cent less than men, a survey by the Institute of Directors and Croner Reward reveals.
The findings show that across companies of all sizes a female director now earns an average of £55,000 per annum compared with the average male executive's basic pay of £72,100. In a further knock to the image of the City, the biggest pay gap occurs in the financial services sector where women bosses earn 35 per cent less than their male counterparts.
The public sector has the smallest gender pay gap at seven per cent, and also has the highest proportion of female directors, 21 per cent.
Bob Michaelson, chairman of the IoD in the West Midlands, said: "Although we are seeing more and more women reaching board level within organisations, the rewards of accomplishing that feat are still being distributed unevenly. If the jobs are the same, clearly the pay should be equal."