The melting of a glacier at one of her favourite walking destinations brought home the impact of climate change, Theresa May has said.

The Prime Minister said the retreat of the glacier in Switzerland had illustrated the need for action as she urged fellow world leaders to step up efforts to respond to the challenge.

She will use the G20 summit in Osaka to push for other countries to act, following the UK’s commitment to cut greenhouse gas emissions to net zero by 2050.

Mrs May will also use the gathering of world leaders in the Japanese city on Friday and Saturday to lobby for the UK and Italy to host the major COP26 climate summit in 2020.

Speaking to reporters accompanying her on the trip, she said the UK’s net zero commitment was now written into law, an “important contribution to make sure we’re not contributing to climate change in future”

The Prime Minister and her husband Philip are keen walkers, and she said they had noticed the impact of climate change on their holidays.

She said: “Just as a small example of why this is important, as you know, Philip and I go walking, not just in Wales but also in Switzerland, and there’s a particular place we go to where over the last decade you see the glacier retreating quickly.

“This has brought home to me the issue of climate change.

“But the G20 represents 80% of emissions, so actually it’s not just what the UK does, it’s about what we can do together.

“So I’m going to be taking a message to the other leaders of them … following on the UK’s lead and acting on this issue.”