Parts of five Tube lines were suspended during the rush hour because of the weather and a number of stations were closed because of ice on the platforms.

Most mainline train services into the city were also badly disrupted.

Many drivers complained that the roads had not been gritted despite the snow being forecast days in advance.

Despite the well-forecast snow falling for nearly 10 hours, none of the local main roads appears to have been gritted Avril Macdonald, East Finchley

London Underground said there was widespread disruption on the network because of the conditions.

Those worst affected were the lines running to the north and west of London.

With the Central and Waterloo and City lines still closed after Saturday's derailment there was frustration among commuters.

Sections of three lines were still closed at midday and there were delays on four others.

To add to the chaos, a fire alert closed the Piccadilly Line between King's Cross and Cockfosters.

A crowded Tube train was evacuated between Wood Green and Bounds Green while firefighters investigated.

The scene was declared safe at 0915 GMT.

One commuter, who e-mailed BBC London, gave up trying to get to work.

Severe delays

Bakerloo Line Jubilee Line Piccadilly Line Metropolitan Line

"I've tried to get into work today and have encountered sheet ice on the pavements and no gritting at all.

"There has been very few buses. The tube in the NW London has been suspended. I decided to come back home as there was no chance that I was going to be able to get into work."

Avril Macdonald said: "I live in East Finchley. Despite the well-forecast snow falling for nearly 10 hours, none of the local main roads appears to have been gritted."

One council told BBC London its gritters had been out all night.

Enfield Borough Council said it had used more than 250 tons of salt and had treated the main routes three to four times.

On the rail network, Thameslink, Thames, South West, Silverlink, WAGN, Connex, Midland Mainline, First Great Western and Eastern and Virgin all suffered major disruption.

Airport delays

There have been delays and cancellations at Heathrow and Gatwick airports and airport operator British Airport Authority (BAA) said it was expecting more through the day.

Stansted Airport re-opened on Friday afternoon but staff shortages caused by the weather meant further delays were expected.

On Thursday evening motorists were stuck for hours across London because of accidents and people driving more slowly in the icy conditions.

Commuters leaving London were stranded on the A1(M), the M25 and the M11 during the night.

More than 200 lorry drivers slept at South Mimms services at the junction of the A1(M) and M25 north of London.

Gridlock took hold in many parts of the city and a spokesman for AA Roadwatch said the situation was the worst seen in London for several years.