The three-strong Catlin Arctic Survey team may have to be be evacuated by plane within the next fortnight as the sea ice has started to break up.

Explorers Pen Hadow, Ann Daniels and Martin Hartley were supposed to continue their trek towards the North Pole until the end of May but pilots are keen to recover them early.

This is due to a combination of the sea ice starting its summer melt and concerns that bad weather may substantially delay any agreed pick-up date.

Their most recent re-supply was nine days overdue because the weather made it too dangerous to land - which meant the team ran out of hot food and had to remain in their tents.

At the start of this week the team were shrouded in thick fog, and had to navigate using the wind direction, as their GPS satellite navigation system is unreliable.

So far they have spent 10 weeks on the ice and covered more than 400 kilometres.

A spokesman for the team said: “It’s not the pick-up we planned, for but pilots have to put their lives at risk to pick up the team.”

The survey team is reportedly happy with the decision, having collected a vast amount of scientific data since they set off in February.

“They’ve had so much experience out there that, either way, they will come away with a clear view of the impact of climate change,” continued the spokesman.

Analysis of the results gathered in the expedition’s first month point to an unexpected lack of thicker, multi-year ice.

Ice measurements showed most of the area travelled over was first-year ice, which is typically thinner, despite designing a specific route that would start them on multiyear ice.

This suggests that rising temperatures near the pole could be melting sea ice at a faster rate.

The team is now being forced to swim across gaps between ice sheets more frequently.

“I never, ever relax here,” said navigator Ms Daniels, who nearly plunged through ice into freezing water two weeks ago. “I never forget its power.”

*Put your questions direct to the Catlin Arctic Survey team - email them to lwaters@london.newsquest.co.uk