Around 140 migrants attempting to cross the English Channel to the UK were picked up by a French maritime rescue operation in the early hours of Saturday morning.

The complex operation, which deployed a number of rescue boats, began on Friday morning when the monitoring station in Saint-Aubin-sur-Mer spotted a migrant boat heading towards Dieppe, a fishing port on the Normandy coast.

Two patrol boats were then used to track the vessel as it made its way up to the Pas de Calais, the French authorities said on Saturday.

Around 40 people were waiting in the water off the coast near Berck-sur-Mer for the “taxi-boat” late on Friday.

Lifeboats monitored them, fearing they would be stranded by the tide, the maritime prefecture explained. And when they did become stranded, they were taken to the beach to be met by the fire and rescue service.

The boat then resumed its northward journey at around 1am, and reached another beach where 82 people were wearing life-jackets waiting to board.

At this time, there were around 20 people already on board the small boat, the prefecture said. Those waiting for the dinghy decided against boarding due to bad weather, and were again met by French rescuers back on land.

Eventually, those on board abandoned their attempt to cross at around 3.30am.

One child received medical attention for hypothermia. In a statement on Saturday, the French maritime prefecture said: “Determined to reach the United Kingdom, migrants attempting the crossing in precarious boats refuse assistance offered by French resources, accepting it only in cases of extreme emergency.

“Given the inherent fragility of these systematically overcrowded vessels, the decision is made not to force migrants onto state rescue ships, thus avoiding endangering lives in the event of a shipwreck.

“The maritime prefecture for the English Channel and the North Sea warns anyone considering crossing the Channel about the risks involved.”

Small boats used by migrants to make the journey across the Channel have been getting increasingly overcrowded. A record 230 people arrived to the UK in a single boat on Monday.

The inflatable boat was seen “buckling” in the water and could have led to a tragedy, according to French rescuers. The French lifeboat crew based at Berck-sur-Mer said the dinghy was 15m (49ft) long and was already carrying around 50 passengers when it was spotted heading towards a beach to pick up more.

French rescuers said that around 30 people ended up in the water during the rush to climb aboard the vessel at 5pm last Sunday, and had to be rescued.

The dinghy then headed towards the UK and was “buckling under the swell”.