Holidaymakers are set to resume their Christmas getaways after an unexpected strike in France, which caused cross-Channel rail services to be suspended, came to an end.

The industrial action affected Eurostar – which operates passenger services to and from London St Pancras – and Eurotunnel Le Shuttle, which runs vehicle-carrying trains to and from Folkestone.

At least 30 Eurostar trains were cancelled on Thursday with services not resuming until Friday, but the company said it will run six extra trains between Paris and London into the weekend.

It came as Storm Pia brought snow and ice warnings across in Scotland today. 

Le Shuttle services will resume this evening, as festive traffic is set to be at its worst today with drivers told to avoid rush hour as Storm Pia brought a snow and ice warning.

Eurotunnel, whose French site staff carried out strike action, said: ‘Eurotunnel management and trade union representatives have reached an agreement at the end of a day marked by strike action which led to the closure of the terminals and the interruption of services since midday.

‘This agreement means that Le Shuttle services will resume progressively this evening and Eurostar tomorrow morning.

‘Eurotunnel welcomes this agreement and reiterates its apologies to all Le Shuttle customers as well as Eurostar passengers and rail freight operators whose traffic has been impacted by this strike.’

Eurostar said: ‘Train traffic will resume tomorrow, with a normal timetable out of London, Paris and Brussels.

‘To help support our customers who could not travel because of the Eurotunnel strike, Eurostar will run six extra trains between Paris and London’.

The high-speed rail service will run an extra two trains each on Friday, Saturday and Sunday.

‘Customers who have been affected today have received direct communication about their journey and had the option to exchange their tickets free of charge or claim a refund,’ Eurostar added.

Student Grace Ferris, 27, said it was a ‘massive inconvenience’ that she missed her Eurostar train back to Manchester for Christmas due to the strike and had to stay in a hotel in Paris.

Ms Ferris, who lives in Barcelona, waited in Gare du Nord for ‘a couple of hours’ and booked a next-day flight to Edinburgh, before a Eurostar ticket for Friday became available and she bought that instead.

She said the staff at Gare du Nord ‘were kind of polite but they were just obviously so unhelpful, like they’re just saying you have to figure it out yourself and find another way’.

The suspension in cross-Channel rail services led to widespread disruption.

The number of cars on Britain’s roads during the festive period is reportedly set to be up 20 per cent up on last year. 

The M20 coastbound carriageway between Junctions 8 and 9 was temporarily closed.

Kent Police announced the ’emergency measure’ to allow freight bound for the continent to queue on the empty section of motorway to try to minimise disruption to Kent’s wider road network.

The force has so far not announced its reopening.

The Port of Dover continued to report a 90-minute wait time for tourists at French border control, but said it was ‘expected to clear over the coming hours’ as Le Shuttle recommences its cross-channel services.

Earlier, news agency Reuters obtained a statement from Getlink, which owns the Channel Tunnel and operates Eurotunnel Le Shuttle services, which said: ‘Today’s call for strike action by representatives of Eurotunnel’s French site staff unions has resulted in the complete interruption of service and the closure of our terminals in France and the UK.’

The company reportedly added that trade unions had rejected an offer of a bonus worth 1,000 euros (£867) per employee, demanding a payment worth three times as much.

Strong winds were also disrupting the Christmas getaway on Britain’s domestic railway.

Trains from London Euston were affected by damage to overhead electric wires, and services continue to be disrupted even after engineers reopened the railway.

Ross Haynes, 31, said he was travelling to visit family members in Manchester when his train was cancelled at Euston station.

The communications professional based in west London said: ‘Obviously, I’m very disappointed. I was looking forward to getting up to Manchester and seeing my family.

‘I was on the train, headphones in, podcast on and ready to go. Suddenly, everything was cancelled and we were turfed off.

‘It’s very frustrating and has led to absolute chaos.’

TransPennine Express urged passengers to avoid travelling to or from Edinburgh all day on Thursday.

The RAC estimated 13.5 million leisure journeys by car would take place across the UK between Friday and Sunday, up 20 per cent on the three days before Christmas Day last year.

Road congestion was likely to peak on Friday – the last working day before Christmas Day – as drivers embarking on leisure trips competed for road space with commuters and business traffic.

Motorists were being advised to travel before 11am or after 6pm if possible to reduce the chance of being stuck in long queues.

Likely traffic hotspots on the M25 identified by transport analysis company Inrix include clockwise between junction 7 (for the M23/Gatwick Airport) and junction 16 (for the M40/Birmingham), and anti-clockwise between junction 17 (Rickmansworth) and junction 12 (for the M3).

Other motorway stretches expected to see long queues included the M1 north from Woburn, Bedfordshire, to Daventry, Northamptonshire, and the M6 south from Wigan, Greater Manchester, to Stafford, Staffordshire.

National Highways said it had removed more than 1,000 miles of roadworks on England’s motorways and major A-roads, meaning 98 per cent of its network would be free of cones over the festive period.

Network Rail is preparing to launch its festive engineering works, which will cause disruption to journeys.

London Paddington will be closed between Sunday and December 27, meaning no mainline trains will serve Heathrow Airport during that period.

London King’s Cross will also be closed on Christmas Eve.

Outside of the capital, an engineering project near Southampton will cause some disruption to services, as will work to build the new Cambridge South station.

No trains will operate on Christmas Day, while a very limited service will run on Boxing Day.

Meanwhile, millions of people are heading to airports to catch flights to spend Christmas overseas.