Cars skid off the road in a 15-vehicle pile-up as Britain braces for travel chaos on the first day of the coldest week of winter as temperatures dip to -7C

• Outbreaks of snow and freezing temperatures will make this week the coldest of the winter, forecasters warn
• Series of weather warnings have been put in place, with widespread ice and sleet due throughout next week 
• The mercury could plummet as low as -7C in some parts of UK, with sub-zero temperatures widely expected
• Commuters in south east of England are facing treacherous conditions during this morning's rush hour 

Sub-zero temperatures have led to treacherous conditions across Britain's roads this morning, with heavy snow and ice closing a busy motorway after a multi-vehicle crash.
Many parts of the UK are facing travel chaos this morning as commuters wake to snow and ice on the first day of the coldest week of winter.
Snowshowers throughout the night have left dangerous conditions for travellers on the M20 in Sussex and Kent up towards Lincolnshire, while freezing fog in Northern Ireland and Scotland have badly affected visibility.
Drivers have already suffered the consequences of the poor conditions in Kent, with five multiple-vehicle collisions involving 15 cars taking place between junction 8 and 9 of the M20 last night.
Meanwhile, there are severe delays on the southbound A1 around the entry and exit slip of the A5135 due to roadworks.
And there are delays on some Southern Rail lines due to ice preventing trains getting electricity from the third rail between Hastings and Eastbourne.
A yellow warning for snow and ice remains in place for London, southeast England and parts of East Anglia until 10am, where temperatures are expected to rise across the country to around 4 or 4C.
Widespread sleet is expected to fall throughout the week with slush and ice causing potential hazards.