Britain's broken borders were starkly exposed on Saturday as Channel migrants boarded dinghies in front of smirking gendarmes while outbound Bank Holiday travellers were forced to wait for hours in ferry ports by French border guards.

Thousands of families planning school half-term getaways on the Continent had to endure sweltering queues of more than four hours at the port of Dover before French police suspended new EU border checks to ease the gridlock.

Port officials had grown increasingly concerned at the lengthening traffic queues, with 18,000 passengers due to travel, as temperatures soared to levels that prompted officials to issue heat health alerts.

Under the EU's new entry-exit system (EES), people from non-EU countries, such as the UK, must have their fingerprints registered and their photograph taken to enter the Schengen Area of 29 European nations.

But with French police having to manually create traveller records until an automated system is in operation, the decision was taken to revert to traditional, speedier border checks to tackle the gridlock.

According to an insider, the new automated system has been riddled with problems, including concerns over the collection of personal data and long delays causing missed departures.

Doug Bannister, the chief executive of the Port of Dover, told the BBC: 'The challenge that we have had is the introduction of the full EES regime since April 10 that has put restrictions on what Police aux Frontières, the French of immigration police, can do.

'They've been working flat out this morning, they've provided the right number of resources, but the process itself was slow. 

'So, in order to ease the congestion, they reverted to a more manual process at this point in time, for a period, just to clear through the congestion.' 

Travellers using Eurotunnel to reach Calais fared little better, with three hour delays reported as border checks caused tailbacks at Folkestone. Passengers missing planned departures were being boarded on later trains.

Meanwhile, on the other side of the Channel, people-traffickers were taking advantage of favourable sea conditions to pack dinghies and small boats bound for the Kent coast.

Scores of migrants, many wearing hi-visibility jackets, were seen wading through the sea off Dunkirk with children on their shoulders in front of watching French police carrying riot shields.

Almost 400 migrants crossed the Channel in small boats on Friday, with similar numbers expected over the holiday weekend because of the improving weather conditions.