By midday today, Monday 6 January, the average FTSE 100 chief executive's pay will already have exceeded the annual salary of the average UK worker.
Bosses from the 100 largest listed UK companies receive an average of £4.22 million, according to research by the High Pay Centre, up 2.5% from a year ago.
This is 113 times the median full-time worker’s pay of £37,430, which has increased 7%.
The calculations, which are based on the most recent available figures from companies' annual reports and official pay data, are designed to show that, like last year, CEOs only need to work less than three days to surpass the median worker's pay for a whole year.
A decline in trade union membership was noted by the High Pay Centre as a key factor in the widening gap between 'fat cat' pay and workers.
A charter for fair pay published by the campaigning organisation last autumn backed most of the measures in the government's Employment Rights Bill and called for further measures giving workers more of a voice in the running of companies.
As ever, the annual study prompted calls for action from unions.
Paul Nowak, general secretary of the Trade Unions Council, said: "Every working person plays a part in producing Britain’s wealth. But while millions of low-paid workers are still feeling the effects of the cost of living crisis, people at the top are taking more than their fair share.
"The government’s Employment Rights Bill will help many workers by improving pay bargaining rights and job security. We also need reforms to rein in boardroom greed, including seats for workers on executive pay committees."