A race to the South Pole involving Britain’s Prince Harry and teams of injured troops has been cancelled due to safety concerns, but the veterans will trek on together to the globe’s most southerly point.

The Walking With The Wounded charity said on Saturday that five days into the gruelling trek, “it became obvious that underneath the concrete determination of all the team members, the harsh reality of the Antarctic was starting to take its toll”.

The three teams, made up of wounded veterans from Britain, the US and the Commonwealth (represented by Canada and Australia), will trek the final 112km together and aim to arrive by next Friday or Saturday, the charity said.

Harry, the 29-year-old fourth-in-line to the throne, is a patron of Walking With The Wounded and had been trekking with the British team.

The charity’s expedition director Ed Parker said the teams had been progressing well but the “unprecedented terrain” had placed a lot of stress on the wounded veterans, who include seven amputees.

“With careful consultation from our doctor and race team, we have put the race on hold,” Parker said.

“This does not mean that the expedition is over. Far from it. We came down here, determined to get 12 men and women, all injured in conflict, to the South Pole, and so we will.”

The veterans are enduring temperatures as low as minus 35 degrees Celsius and wind speeds of about 80km/h.