The housewives, surgeons, teachers and policewomen making the historic journey from Resolute Bay, in the northern-most tip of Canada, to the Pole reached the halfway point last week. The journey across the cracking ice-sheet has been divided between five relay teams, each of four women, who are airlifted in as the previous team's supplies run out.
The first three teams, Penguin Alpha, Bravo and Charlie, have covered 200 miles between them, despite the drifting of the ice-cap which meant Penguin Charlie were at times almost running to stand still. Penguin Delta and Echo have to cover the final 200 miles between them, with the last team due to set out in the next fortnight.
"The wonderful thing about getting there," said Caroline Hamilton, speaking from base camp in Resolute Bay, "is that it will be our North Pole." As the woman who dreamed up the expedition two years ago, she has endlessly imagined herself at her destination, walking in a circle through all the different time zones. "Because the geographical North Pole moves all the time it will be a very private experience, a different Pole from anyone else's."
A keen explorer of far-flung terrain, the 33-year-old film financier's dream grew from a fascination with deserts into a desire to achieve something no one else had. "We made it a relay so that ordinary women who couldn't afford to take months off work could take part," she explained.
She is mystified by the idea that women do not take to the Arctic because polar bears smell them more easily they do male explorers and might attack them. "It sounds like a conspiracy to keep the North Pole for men," she said. Whatever the truth of the theory, it appears polar bears are far too sensible to venture as far north as Penguin Echo will go.
As a member of Echo, Ms Hamilton shares the pressure of being in the final team. "The others who have gone before have done such an amazing job that we are all terrified of letting them down," she said. "Part of the dilemma is that if we carry extra food and water, to keep us going for longer, that will weigh us down so we won't be able to cover so much ground each day.
"If we run out of supplies without reaching the Pole we'll just have to keep going without wasting time sleeping."
The women will also be racing the effects of spring. Temperatures have risen by 25 degrees since Penguin Alpha set out in temperatures of minus 50C. This is less debilitating for the final team, but also means the ice-cap is cracking. If Penguin Echo fail to reach the Pole by the end of the month the airlift back may be impossible.
For now, Ms Hamilton, Zoe Hudson, Pom Oliver and Lucy Roberts are under starter's orders in splendid isolation, waiting for news of Penguin Delta and training on the sea-ice surrounding Resolute Bay. "It is beautiful here at the top of Canada," Ms Hamilton said. "The view is white as far as you can see, except for the blue icebergs and the grey segments of soft ice."
As the Independent on Sunday broke the news that Labour had come in from the cold, that silent landscape resounded to the whoops of delight and groans of anguish from Britain's most northerly community of women.