The UK’s over-stretched workers gave their employers £33.6 billion of free labour last year by doing unpaid overtime, according to a new analysis of official statistics from the TUC.

The TUC’s calculations were published on 24 February, to mark its 13th annual Work Your Proper Hours Day. The union body says prior to this day, the average person doing unpaid overtime has effectively worked the year so far for free.

More than 5.3 million people put in an average of 7.7 hours a week in unpaid overtime during 2016. This is equivalent to an average of £6,301 they have each missed out in their pay packets.

TUC general secretary Frances O’Grady urged workers to “make a stand” on 24 February, making sure they took a proper lunch break and went home on time.

Commenting on the uncertain prospects for the working time regulations, which were introduced as a health and safety measure, she said: “The government still doesn’t have a water-tight plan to stop working time protections getting weaker when we leave the EU. The prime minister should promise to put a guarantee into our future trade deals with Europe that British workers will have a level playing field with EU workers.”