A bitterly cold snap expected to sweep across the UK next week has put hundreds of gritters back on standby.

Met Office forecasts are warning of an impending change in the weather, with temperatures expected to plummet, snow forecast for northern areas and on higher ground and a wintry mix of bitterly cold rain, sleet and snow for others.

Ice, says National Highways, is likely to be 'an ongoing hazard' from Sunday and is warning motorists to be aware of possible dangerous conditions and of the need to give gritters plenty of space to work on the roads.

National Highways has road temperature and weather forecast contracts with independent meteorological experts between October and April to compliment the national Met Office weather forecast, which provides a high level of precision about changing road surface temperatures to help workers know when and where to grit.

Met Office forecaster Aidan McGivern said people will notice a change come the end of the weekend as January's mild temperatures are replaced with much colder weather.

He explained: "Next week, the jet stream is a bit more amplified and it’s coming at the UK from the northwest rather than from the west like recent days. This subtle change into the start of next week will see colder weather coming in and rather than prolonged bouts of rain from the west, we’re likely to see rain and showers coming from the northwest.

"These showers from the north could fall as snow over the high parts of Scotland, northern England and Northern Ireland later in the weekend, and as we move through next week often below average temperatures could support a mixture of rain, hail sleet and snow. Most of any snow accumulation is likely over higher parts of the northern UK.

"However, at this point significant differences in the computer models emerge. Most solutions lead to some unsettled weather, but the distribution of the rainfall and where we’re likely to see any snow varies as well."

Darren Clark, severe weather resilience manager, at National Highways said gritters are ready to respond.

He added: "Whilst gritters travel up to 50mph when spreading road users need to be aware of the road and traffic ahead of them. We have had an incident this winter where the rear of a gritter was hit. We ask all road users to give our staff time and space to do their job safely, and if you see our vehicles indicating to change lanes please do what you can to safely help us to do this.

"Not all roads will need treating on any given day. Gritters may need to go out in some regions if road temperatures fall below 1C and if there is a risk of frost or ice forming, but not in other areas if conditions are not as cold.

"For road users we suggest always check the weather forecasts, plan your journey, allowing more time for travel in wintry conditions, and carry out regular vehicle checks such as your coolant and tyre pressures."

National Highways has a new fleet of 252 Volvo gritter vehicles all of which are involved in salt spreading this season. The investment now means the organisation has around 530 gritter vehicles available this winter to treat the country's motorways and major A-routes.