According to absence management firm FirstCare, absence caused by transport problems jumped to 20,300 cases yesterday (Monday), compared to just short of 3,000 on a normal day.

Aaron Ross, chief executive of FirstCare, said: “The high level of non-medical related absence is reminiscent of the snow chaos cause at the beginning of the year and at an average direct cost of £168 per day of absence, it will cost UK business over £3m a day.

“Our nurses have been taking calls from stranded employees across the world, many of whom have been trying to return since late last week. We are also hearing from relatives who are looking after children and dependants of those stranded and as a result are unable to go to work themselves.”

The ban on flights also has implications for employers’ payroll departments. Payroll staff have had to decide whether the unplanned absence of stranded staff affects their annual holiday allowance or should be treated as unpaid or paid leave.

Lindsay Melvin, chief executive of the Institute of Payroll Professionals (IPP), said: “Payroll departments need to take the appropriate steps to work out whether there are contractual obligations to pay employees even if they cannot come into work.”

According to law firm DLA Piper, employers have no obligation to pay staff if they are absent from work, even in the case of unavoidable travel problems.

When asking other staff to cover for absent colleagues, employers need to consider their health and safety obligations and working-time regulations. It also depends on the contract of employment whether it is reasonable for an employer to ask other staff to fill in for absent colleagues or ask stranded employees to work from abroad.

However, an employee who can reasonably work from overseas and chooses not to would usually not be paid or required to take the time as annual leave. Employees in this situation could also face disciplinary action.

Guy Lamb, employment partner at DLA Piper, said: “As with the issues caused by the snow earlier in the year, employers are not bound to pay employees who do not turn up for work, even if they have been grounded by the flight restrictions.

“However, it is likely employers will use their discretion and not deduct pay from employees in this situation, and while failure to turn up to work is technically a disciplinary offence, it would probably be unfair for an employer to take such action if the employee has taken all reasonable measures to get back to the UK.”