LONDON (Reuters) - Heavy snow disrupted air and rail travel in northern Europe on Monday, halting flights at Heathrow airport and bringing traffic in London almost to a standstill.

Tens of thousands of commuters were advised not to attempt the journey into work in London, experiencing some of its worst snow in almost 20 years. Buses were taken off the roads and hundreds of schools were closed across the country, leaving children to play and build snowmen in parks and gardens.

“I’d rather be sledging than at school,” said 7-year-old Georgie Cunliffe, in a London park.

Forecasters said Britain would be gripped by a second day of freezing weather on Tuesday with more heavy snow spreading across the country overnight.

Conditions familiar to eastern Europe and other northerly countries notoriously pitch Britain into chaos, its infrastructure ill prepared for the cold.

Northern France also had difficulty as snow blanketed Paris and surrounding countryside bringing major air, rail and road systems to a halt.

London business leaders said the estimated cost to the capital alone could be as much as 48 million pounds in lost productivity. The country’s Federation of Small Businesses estimated that continuing bad weather on Tuesday could cost the economy more than one billion pounds.

All flights in and out of Heathrow, a major international hub, were cancelled for a period before a limited service resumed with long delays and cancellations. One of its two runways was closed.

A Cyprus Airways jet at Heathrow slipped off a taxiway after arriving from Larnaca but came to a safe halt. No-one was hurt.

Gatwick, Stansted and Luton airports reported delays and flight cancellations. London City Airport, which serves the financial district, was closed for the day.

Dublin, Cork and Belfast airports were also forced to cancel some flights.

Large parts of London’s underground rail network were suspended, forcing commuters to walk or seek those taxis prepared to stay out on the roads.

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WEATHER WARNING

Highway authorities warned of hazardous driving conditions in southern and central England and advised people not to drive unless absolutely necessary.

Prime Minister Gordon Brown said the government was “doing everything in our power to ensure that the services, road, rail and airports, are open as quickly as possible.”

The heaviest snow fell in southern England. Epsom in Surrey had depths of 31cm (12 inches), south London had 28cm and the North Downs in Kent saw 25cm.

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The Met Office extended severe overnight weather warnings for large parts of the country, including Scotland, Wales, Yorkshire and the Midlands.

Weather experts said southeast England was experiencing some of its worst snow since the early 1990s.

The international rail operator Eurostar also reported delays due to snow in Britain, France and Belgium.

Many workers attempted to walk to their offices, but London’s Chamber of Commerce business organisation said lost productivity could cost the capital dear at a time when the British economy is in recession.

In France, traffic jams were recorded on roads leading into the capital during the rush hour and the Paris transport authority said many buses had to be cancelled.

So far, this winter has been Britain’s coldest in more than a decade and forecasters expect the cold weather to continue for several more days with freezing winds blowing in from Russia.