Our laws provide that workers can only receive payment in lieu of untaken statutory holiday at the end of their employment. 

Under the Working Time Regulations workers have to use their holiday entitlement each year or lose it. They can't carry it over or receive payment for untaken holiday.   The only exception is where a worker is too ill to take a holiday and in these circumstances, he is allowed to carry over some untaken holiday into the next holiday year. Even if this applies, the worker is not entitled to be paid for it unless his employment is subsequently terminated.

If the ECJ agrees that workers should be entitled to carry holiday over to the next year where they are unable to take holiday for reasons beyond their control our laws may have to change and more workers may try to carry over holiday or receive payment for untaken holiday. That said, it will be very difficult for workers to prove that they could not take a holiday unless their requests were denied or work pressures were so extreme there was simply no time available to take a holiday.