The AA has issued its first “amber traffic warning” for Friday and Saturday (July 29 and 30) as severe congestion is anticipated, with it expected to peak between 11am and 3pm on both days.

This is due to a combination of the first switchover days for holiday lets during the school summer holidays in England and Wales, a rail strike, the Commonwealth Games in Birmingham, and the start of the Football League season in England.

Roads approaching Dover and the Eurotunnel terminal at Folkestone are expected to be busy, as well as those serving Devon and Cornwall, such as the M5, A303 and A30.

The south-west and western sections of the M25, the Bristol M4/M5 junction, and the M6, M42, M1 and M62 are also vulnerable to jams this weekend.

Richmond and Twickenham Times: Rail strikes plus a weekend of sport is expected to contribute to the congestion (PA)Rail strikes plus a weekend of sport is expected to contribute to the congestion (PA)

Jack Cousens, head of roads policy for the AA, said: “With holiday let switchover day starting on Friday mixed with train strikes and a huge weekend of sport, we are concerned that drivers will experience delays across the network, with the south of England particularly vulnerable.

“All eyes will be on Dover and Folkestone, but we believe changes have been made throughout the week and we will keep our fingers crossed for a smoother trip across the Channel.

“Breakdowns can make jams worse and last weekend we saw a rise in breakdowns where vehicle checks had not been carried out before setting off.

“Spending 10 minutes checking tyres and fluid levels before setting off can make a big difference in helping people getting to their destination.”

National Highways, which manages England’s motorways and major A roads, said: “Drivers travelling in and around Kent are advised to plan ahead as this weekend is likely to be extremely busy.

“Operation Brock contraflow remains in place on the M20 and is part of a series of measures to improve Kent’s resilience and ensure the smooth flow of traffic through the region in the event of disruption to services across the English Channel.”