Safety warnings were issued tonight as the heaviest snowfall of the season crept in.

A light dusting across south east England on Thursday afternoon precedes up to 15cm (5.9in) in areas around London overnight, forecasters warned.

Temperatures remained resolutely above freezing across the UK at lunchtime but they would plunge as low as minus 9C (15.8F) by Thursday night in the Scottish Highlands, MeteoGroup UK, the weather arm of the Press Association, said.

With treacherous conditions during festive preparations, the Government warned the public to keep an eye on vulnerable members of communities.

Chances of a white Christmas continued to "hang in the balance", experts said.

Andy Ratcliffe, a forecaster for MeteoGroup UK, said snow was not settling in the UK on Thursday - but a heavier blanket was on its way.

"Parts of the UK have been hit by sleet rather than snow today," he said. "But tonight it's pretty certain to turn to heavier snow, particularly in the south-east.

"While there could be as little as 2cm in central London, areas just outside - particularly around the Chiltern Hills - could see as much as 15cm.

"Western Kent and Surrey will see snowy conditions into Friday. This could be the heaviest snowfall of the winter so far for areas."

Northamptonshire and northern parts of Hampshire were also identified as areas likely to wake up to a snowy scene on Friday.