BORIS Johnson has downplayed the prospects for the COP26 summit, saying he is “very worried” it will fail to deliver the agreements needed to tackle climate change.

With more than 120 world leaders due to arrive in Glasgow in a few days, the Prime Minister said the event, which is under the UK’s presidency, remained “touch and go”.

Mr Johnson, who was criticised for recently going on holiday to Spain instead of working on preparations for COP26, said success was possible but looked “very, very tough”.

He also caused controversy by telling a children’s event at Downing Street that recycling plastic “doesn’t work” and was “not the answer” to climate change.

“It doesn’t begin to address the problem. You can only recycle plastic a couple of times, really. What you’ve got to do is stop the production of plastic,” he said.

“The recycling thing is a red herring.”

The aim of COP26 is for all countries to set out firm, short-term plans to cut their carbon emissions and so collectively keep the rise in global temperatures, relative to pre-industrial levels, below 2C by the end of the century, and below 1.5C if possible.

However the leaders of some of the world’s major emitters are expected to stay away, including China’s Xi Jinping, whose country proudces a quarter of global emissions.

Mr Johnson, who meets world leaders in Glasgow next week, told the eight to 12-year-olds at his Downing Street event: “We need as many people as possible to go to net zero so that they are not producing too much carbon dioxide by the middle of the century.

“Now, I think it can be done. It’s going to be very, very tough, this summit.

“And I’m very worried, because it might go wrong and we might not get the agreements that we need. It’s touch and go.”

The PM also said it was “very, very far from clear that we will get the progress that we need” though he praised Australia’s “heroic” decision to commit to net zero by 2050.

Number 10 later said Mr Johnson was setting out the “realistic situation” about the chances of COP26 being a success.

The PM’s official spokesman said: “We have made some progress with a number of countries, Saudi Arabia has come forward with some commitments, for example.

“But the Prime Minister was simply setting out the realistic situation that bringing together countries from around the world to sign up to ambitious targets such as these that require tangible commitments is difficult and challenging, and will require some intense negotiation.”

During a question session with the schoolchildren, Mr Johnson also attacked Coca-Cola.

He said: “There are about 12 companies at the moment, 12 big corporations, that are producing the overwhelming bulk of the world’s plastics. Big famous drinks companies that you may know but I won’t name. I don’t know why not, but I won’t name them.”

He then contradicted himself, and went on: “Coca-Cola, for instance, and others, which are responsible for producing huge quantities of plastic, and we’ve got to move away from that and we’ve got to find other ways of packaging and selling our stuff.”

He then said recycling “doesn’t work” and reducing plastic production was key.

He said: “Recycling isn’t the answer. Recycling… it doesn’t begin to address the problem.”

He said “the only answer” was “we’ve all got to cut down on our use of plastic”.

Appearing with him, WWF UK chief executive Tanya Steele said: “We have to reduce, we have to reuse - I do think we need to do a little bit of recycling, PM, and have some system to do so.” 

But Mr Johnson replied: “It doesn’t work.”

Recycling Association chief executive Simon Ellin accused Mr Johnson of having “completely lost the plastic plot”.

Reacting on behalf of the industry, he told the BBC Radio 4’s World At One programme there was shock at the remarks. 

He said: “It’s very disappointing. I think he has completely lost the plastic plot here, if I’m honest. We need to reduce, and I would completely agree with him on that.

“But his own Government has just invested in the resources and waste strategy, which is the most ground-breaking recycling legislation and plan that we’ve ever seen, with recycling right at the front of it. So he seems to be completely conflicting with his own Government’s policy.”

The PM’s official spokesman said Mr Johnson continued to encourage people to recycle.

“The Prime minister was setting out that recycling alone is not the answer,” he said.

“We’re taking a wide range of action across society to cut plastic pollution.

“Simply relying on recycling alone, as the Prime Minister set out, would be a red herring - we need to go further and take wider action.”