A union chief lashed out at Ed Miliband for having 'no plan' to make Net Zero work today as Labour infighting escalated.

Unite general secretary Sharon Graham swiped that someone who 'believes in Britain' should be made Energy Secretary.

The jibe, in a round of interviews, came after an extraordinary intervention by Tony Blair exposed deep rifts in the party over Mr Miliband's approach.

Sir Tony said a strategy based on phasing out fossil fuels in the short term or curbing consumption was 'doomed to fail'.

He cautioned that Brits would resent 'being asked to make financial sacrifices and changes in lifestyle when they know that their impact on global emissions is minimal'.

The comments, in a foreword to a report by his think-tank, sparked a furious backlash from some Labour elements, although other MPs and ministers insisted he had been right to voice concerns. 

No10 refused to deny it asked the Tony Blair Institute to issue a clarification yesterday, with Keir Starmer adamant at PMQs that the former PM was 'absolutely aligned' with the government's plans.

The PM's spokesman praised Mr Miliband - but notably stopped short of guaranteeing he will remain in post for the rest of the Parliament. That promise has been made about Foreign Secretary David Lammy and Chancellor Rachel Reeves. 

Asked this morning for her view on Mr Miliband, Ms Graham said: 'I'm not going to get into the personalities of individual ministers, but what I will say is that there is an absolute lack of a plan.

'We have a plan to transition to wind manufacture, carbon capture, hydrogen, ready sitting and waiting, costed properly… and you get 'computer says no, let's discuss it another time'.

'Somebody needs to be in that post that believes in Britain, believes in these skills, believes in the national security of the country.'

Challenged whether she agreed with Sir Tony's comments, Ms Graham told Times Radio: 'Workers want net zero, my members have no problem with Net Zero. The problem that we've got is that there is no investment currently about how we get to that and also secure jobs.'

She pointed to developments at Grangemouth, where oil refining ended earlier this week, and added: 'The problem is that the jobs part of this is not being discussed.

'There hasn't been one single thing done so far that I can see in terms of investments on wind manufacture, in terms of investments into areas like sustainable air fuel… all of those things have not happened, and you cannot just plough on regardless and throw all of these workers on the scrapheap.

'I have said to the Labour Government that they need to have a joined up industrial strategy.

'You cannot offshore your carbon responsibility. It's the planet we're trying to save, not a part of Scotland.'

The GMB union has described the Government's energy policy as 'bonkers'. 

General Secretary Gary Smith said it was 'absolute madness' to be cutting off investment into North Sea oil and gas, and warned of a 'growing sense of betrayal'.

Asked yesterday if Sir Keir had confidence in Energy and Climate Change Secretary Mr Miliband, the PM's official spokesman told reporters: 'Absolutely. He's doing a fantastic job.'

But pressed on whether he would stay in post for the rest of this Parliament, the spokesman merely said: 'The PM absolutely backs the Energy Secretary. He does a great job in winning the global race for the jobs of the future.'

Environment Secretary Steve Reed yesterday rejected suggestions that Sir Tony's intervention amounted to a 'public tantrum'.

'He's making a valid and important contribution to a very significant debate,' Mr Reed told Times Radio. 'I agree with much of what he said, but not every word of it.'

Sir Tony argued that most political leaders 'would like to start taking some of the hysteria out of the climate debate but are reluctant to be the first to do so'.