内容摘要：In their statement the government said: "It's vital we take the time to work through the range of responses to our consultation, but equally important that we put in the groundwork now as we consider the next steps.

In their statement the government said: "It's vital we take the time to work through the range of responses to our consultation, but equally important that we put in the groundwork now as we consider the next steps.

Organisers said the use of xenon had made such a fast ascent possible. But the science around using the gas remains disputed and many in the mountaineering industry have criticised it.Although this expedition is a record Everest ascent without acclimatising in the Himalayas, it's not the fastest Everest time.

That record still belongs to Lhakpa Gelu Sherpa, who climbed from base camp to the summit in 10 hours and 56 minutes in 2003 – but he did this after acclimatising on the mountain.The xenon-aided team, accompanied by five Sherpa guides and a cameraman, reached the 8,849-metre (29,032-foot) summit early on Wednesday, and began their descent soon afterwards."They started on the afternoon of 16th May and summited on the morning of the 21st, taking four days and approximately 18 hours," expedition organiser Lukas Furtenbach told the BBC.

The four former soldiers, who include veterans minister Alastair Carns, slept for six weeks in special tents before travelling to Nepal to help them acclimatise to decreased levels of oxygen at high altitude.They then flew to Everest base camp from Kathmandu and started climbing straight away, Mr Furtenbach said. They used supplemental oxygen, like other climbers, during the expedition.

Climbers usually spend weeks going up and down between base camp and higher camps before making the final push for the summit.

They need to do that to get used to thinner oxygen levels at high mountain altitudes. Above 8,000m, known as the death zone, available oxygen is only a third of that present at sea level.Until just over a week ago, Artem Kariakin and his unit were making regular trips across Ukraine's border into the Russian town of Sudzha.

He shows me video taken with a phone of their very last trip, as Ukrainian forces retreated from Russia's Kursk region. It shows them making their way past dozens of burnt out military and civilian vehicles.A soldier armed with a shotgun, their last line of defence, scans the horizon for Russian drones. Out of nowhere, one flies towards the back of their truck. Sparks fly, but they keep on going.

Artem says they were lucky - the explosive charge was not big enough to stop them.Another truck nearby was less fortunate. It was already in flames.