Tony Blair sent a shockwave though Labour circles this morning after he appeared to criticise the push to achieve net zero by 2050.

In a foreword to a report by the Tony Blair Institute, the former prime minister said political leaders know that the debate around the policy “has become irrational”.

He also said that the government’s plan to phase out fossil fuels is “doomed to fail”, in what was seen as a dig at Downing Street’s flagship policy to reduce net carbon emissions to zero in the next 25 years.

Keir Starmer is known for sharing many values with New Labour and has taken advice from his predecessor, meaning Blair’s words were a major blow to No.10.

The Tony Blair Institute quickly tried to downplay the split, and claimed the current government has the “right” approach – but it was too late.

The damage was already done, and the story swept through the country, and even secured a mention in PMQs.

Here’s a look at why Blair’s comments completely missed their mark.

Although Blair himself has emphasised the importance of addressing the climate crisis, his words appeared to validate concerns from climate sceptics.

For instance, Reform UK’s deputy leader Richard Tice told ITV’s Good Morning Britain that the party has “newfound fans like Tony Blair” who agree with their anti-net zero policy – although he admitted he was “teasing”.

DUP MP Sammy Wilson adopted the same tone in PMQs when he told Starmer his net zero policy “is not only bad, it is mad” – and claimed even Blair agrees.

Of course, Blair’s former political secretary John McTernan suggested the opposite to Times Radio, saying the ex-PM was just explaining “grievance is the energy source for populist movements”.

He claimed that he was encouraging politicians to engage with “people’s feelings” to deter support for groups like Reform UK – not that Blair was against net zero altogether.

While the former PM might be winning backing from Labour’s opponents, those affiliated with the party said otherwise.

Unite the Union issued a firm warning that Blair’s net zero intervention must be a wake up call for government.

General secretary Sharon Graham said: “Unite is not against net zero but it will not be achieved without serious investment in new jobs.

“Unite has warned time after time, that all the rhetoric about a joined up industrial strategy and future jobs must be backed up with serious investment that actually delivers. What is Labour waiting for? The time to act is now.

“If they fail to do this, then Labour cannot expect workers to support their net zero plan.”

To make matters worse, Blair’s intervention came just before local elections in 23 councils and the Runcorn by-election – the current government’s first big test since it won a landslide in July.

Blair’s remarks were also criticised for being “misleading” amid the already hotly-contested climate debate.

An organisation which promotes debate on climate policy, the Energy and Climate Intelligence Unit said: “Given the clarification the TBI has had to issue, this seems like a bizarre case of naivety on how parts of the media and politicians might misinterpret some of the statements in the foreword.”

The Blair government’s former climate guru, Nicholas Stern – now chair of the Grantham Research Institute – called Blair’s report “muddled and misleading”.

“The UK’s leadership on climate change, particularly the elimination of coal from its power sector, is providing an influential example to other countries,” Stern continued.

“So, too, its climate change legislation and its Climate Change Committee. If the UK wobbles on its route to net zero, other countries may become less committed. The UK matters.”

Stern, who launched a landmark report on climate change in 2006 under Blair’s government, found the costs of inaction outweigh the costs of action.

He warned that the report “downplays the science in its absence of a sense of urgency and the lack of appreciation of the need for the world to achieve net zero as soon as possible”.

Meanwhile, Bob Ward, policy and communications director at the Grantham Research Institute on climate change at the London School of Economics and Political Science, said: “This report provides weak analysis and the wrong solutions. It fails to recognise that the longer it takes to reach net zero emissions in the UK and around the world, the more that households and businesses will suffer from growing impacts of climate change.”

He added that the challenge is to “accelerate the transition away from fossil fuels, not to slow down”.

Helen Clarkson, CEO of Climate Group, said the report set up a “false binary” between climate strategies of either phasing out fossil fuels or investing in new low-cardon technologies.

And even the Social Market Foundation’s Theo Betram – a former special adviser to Blair – wrote on X that his old boss had “got it wrong on net zero” and his words “has only served to help populist opponents” of the policy.

There also appears to be limited public support for Blair’s take.

A recent YouGov poll found 61% of people either strongly support or somewhat support the government’s commitment to cut carbon emissions to net zero by 2050.

Then there’s the fact that Blair’s intervention overshadowed fresh warnings from the government’s climate watchdog, too.

The Climate Change Committee – the statutory adviser on the issue to the government – published a report today calling for Downing Street to go further and faster on climate action, particularly with flood defences.

Chair Lady Brown said: “We are seeing no change in activity from the new government, despite the fact that… it’s clear to the public that the current approach just isn’t working.

“The country is at risk, people are at risk, and there is not enough being done.”

Brown also warned that there were already too many cuts to flood defences, adding: “I can’t be clear enough about our message: we cannot wait to take action.”

But Blair’s remarks overshadowed her points on the environment.

As she later told BBC Radio 4′s Today programme: “My concern is that people might take away a message from that report that we should do adaptation instead of mitigation, and that is absolutely the wrong message.

“We need to do adaptation, because even if we get to net zero by mid-century, there’s still a huge amount of climate change to come, and we need to be ready for that. But we can’t adapt to everything.”