The news is the latest in a series of blows for the chain, currently the focus of the film 'Super Size Me' by Morgan Spurlock, in which he lives on a diet of McDonald's food. The movie is proving very popular with cinemagoers in the UK.
The burger-giant's pre-tax profits in the UK dropped from £83.8m to £23.6m, according to its 2003 accounts filed with Companies House last week.
The report show that the chain has been hard hit by a combination of stagnant sales and rising rents for its UK restaurants.
Increasing competition from healthier food retailers such as sandwich chains like Pret A Manger, combined with an increasing tendency for UK punters to opt for more healthy food options is proving troublesome for McDonald's.
The restaurant chain has already made efforts to make its menu more health conscious with the introduction of salads.
Over the weekend, the company's new chief executive Charlie Bell said that he wanted to bring new sandwiches, being trialled in Canada, on to the UK menu and to associate McDonald's less with burgers and more with heart-friendly food options.
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