Labour has attacked the Prime Minister’s “do as I say, not as I do” approach to Cop26 diplomacy following the conclusion of the crunch climate summit.

Deputy leader Angela Rayner said Boris Johnson “could have done more to be there and to make sure that in that room at those vital opportunities” it was possible to “sway the opinion”.

Ms Rayner also claimed Cop26 President Alok Sharma’s efforts had been “undermined” by the Government’s cut to overseas aid and investment in fossil fuels.

She told BBC One’s The Andrew Marr Show: “We have made some progress and we have to acknowledge that, but we also have to acknowledge that we failed in getting that target of 1.5C and we must keep that pressure on because it will be catastrophic for areas of the world and for our planet, so we’ve got more to do, but we have made some progress.

“We saw minister (Alok) Sharma there, doing his utmost, but Boris Johnson has undermined some of our efforts by the use of fossil fuels, the investment in that, the cutting of overseas aid.

“There’s much more that we can do as a country to set an example globally, to make sure we reach that target.”

Asked if the West should be paying reparations to poorer countries for the cost of climate change, she said: “We have a responsibility to support the poorer countries as well, absolutely, we’ve said that.

“Boris Johnson cut overseas aid whereas I think we should be investing and supporting. At the moment we’ve got a Prime Minister who says do as I say, not as I do – and I think that sends the wrong message out.”

On travel, she said: “(Labour leader) Keir (Starmer) doesn’t use domestic flights, Keir always travels as green as we possibly can… it was actually significantly cheaper to go in a domestic flight (to Glasgow) than it was to use the train, so we need to invest in our public transport services.”

Meanwhile, shadow business and energy secretary Ed Miliband said the UK “should be rewriting that Australian trade deal” over climate commitments.

He told Sky News’ Trevor Phillips on Sunday: “We need to do more to put pressure on all of the big emitters, frankly, that includes India, that includes China.

“It includes countries like Australia… we’re doing a trade deal with Australia and we’ve agreed to drop the Paris temperature commitments from the trade deal. Now, Australia is a real laggard on climate.

“For all countries, climate policy can’t sit on the side of their other approaches, their other policy, it’s got to be at the heart of what we do. We should be rewriting that Australian trade deal.”

Asked if Labour should say the Cambo oil field and the coal mine in Cumbria should not go ahead, he said:  “You’re right, neither of them should go ahead. No prevarication, clarity.

“We cannot have the Cambo oil field going ahead because it’s the equivalent of 18 coal-fired power stations running for a year. We should not be having a new coal mine in Cumbria. Frankly, it looks like total hypocrisy when we are trying to persuade other countries to act.”

Mr Miliband also argued that the Government had “undermined” Mr Sharma by cutting overseas aid.

He said: “I have nothing but praise for Alok Sharma… and the job he did as Cop President, but I’m afraid the rest of the Government didn’t help him and undermined him with decisions like cutting overseas aid, because we were then saying to other countries ‘please step up on climate finance’, when we were stepping back on aid to poorer countries.

“Government needs to make the investment so that it’s financially possible for people to make the change… I’m saying we borrow now to make this investment because it will save money in the long run and it’s the prudent and responsible choice.

“I think the British people are in a very sensible place on this, I think they’re saying we want to go green, we want to do the right thing, but don’t make this a rich person’s luxury.”