New research from leading accommodation site Hotels.com has revealed that as 2009 came to a close, Britain had 5.2 million days of annual leave left untaken.

It is estimated that nearly one in five people (18 per cent) had holidays still left to take before the end of the year, according to the survey, meaning that at least five million holiday days remained unclaimed.

Of those with annual leave left to take, more than a third (34 per cent) had yet to use up their remaining day’s holiday while as many as one in six (15 per cent) still had five working days to book off - for the majority of the UK’s workforce, this equates to a significant proportion (18 per cent) of their total holiday allowance.

The survey which was conducted amongst 800 Hotels.com customers between 7 and 21 December 2009, revealed that one in six Brits had taken less holiday in 2009 than in 2008 - a sign perhaps that the recession forced workers to forgo a day’s holiday.

Alison Couper, Director of Communications at Hotels.com, said “It’s staggering to see how much holiday is left unclaimed. With hotel prices at a record low, 2009 was a fantastic year to bag a bargain and this trend is set to continue in 2010. With over a third of people unable to carry their unused leave into the next calendar year, people should take the chance to use it.”

For workers with unused holiday allocations, Hotels.com is running its January sale until 15th February for stays until 15th April 2010.