The ruling may make companies that offer Permanent Health Insurance (PHI) or enhanced sick pay schemes reconsider their position for fear of being hit by additional charges if a long-term sick employee claims holiday pay.

Under UK law, it is not currently clear if employees are allowed to take holidays while off sick, so any conflict would have to be resolved in the courts until the House of Lords decided either way.

The ECJ has also ruled that employees are entitled to rollover their holiday to the next year, a policy also in conflict with the UK's Working Trade Regulations (WTR).

BPIF head of legal Anne Copley told PrintWeek the cost could be a financial burden for companies.

She said: "Printers will have a bit of time to review their sickness policies before the House of Lords make their ruling but other questions arise. 

"For instance, if you have to pay someone holiday pay on termination, what rate of pay should be used – the current one or the one in place at the time of accrual?"

She continued: "And it is worth making clear to employees that contractual holidays above the 28 days imposed by the WTR will not be treated in this way.

"One of the cases taken to Europe was for the princely sum of about £7.50 due in holiday pay. A fantastic illustration of momentous legal decisions arising out of apparently insignificant sums."

Matt McBride, senior associate at law firm Freeth Cartwright, added: "Depending how the House of Lords rules, there is a potential scenario where a person could be off for two years, come back to work and demand either two years of holiday pay, or ask to take the holiday they've accrued over the two years, and get paid for it.

"This is a significant change because, as it stands, companies tend to keep long-term sick employees on their books because, after the period set by a company, they are no longer obliged to pay them.

"Companies would be more likely to terminate that person's contract if the ECJ's ruling is adhered to."