The praise for Andy Burnham was effusive: ‘He has articulated a clear social-democratic vision for Britain. And attacks about returning the country back to the 1970s won’t work because most voters can’t remember or don’t even know about the 1970s.’

Yet what was most surprising was that this message to me came from a senior figure within .

‘The biggest shame for me was Burnham getting the bounce on the triple-lock. That’s something we should have grasped the nettle on to show we’re different, and willing to do tough things,’ he added.

His words were echoed by another unexpected source: a senior Tory shadow minister who told me: ‘That was very powerful. I think the policies are fundamentally wrong, but it was bold, big-vision stuff.

‘We’re going to have to think seriously about how we respond. Burnham’s proving more effective than I suspected.’

Yesterday the enthusiastic cheers that greeted Burnham’s maiden speech as Labour leader were replaced by hard questions. A number of which he’s struggled to answer.

Asked on BBC Radio 4 Today about his decision to scrap the triple lock on state pensions, he replied: ‘That’s not quite right. I’ve said that we will make an to the triple lock.

‘Now you might say that sounds like clever politician-speak.’ It did. And for a Prime Minister basing his entire political strategy around a pledge to speak truth to power – and the people – it was a clumsy evasion.

Similar confusion surrounded his stance on Europe. On Tuesday, the PM revealed that rejoining the EU was an option under active consideration. But as recently as May, he declared: ‘I am not proposing that the UK considers rejoining the EU. I respect the decision that was made at the referendum.’

Although the obfuscation may be embarrassing, there is no point people on the Right sticking their heads in the sand. Like it or not, on Tuesday the Prime Minister seized control of the political agenda.

In the hours after his speech, Survation commissioned a poll of his triple-lock proposal. Some 64 per cent supported it, while only 15 per cent were opposed. What’s more, backing for his plan transcended the age groups. Among those aged 55 to 64, 61 per cent said the idea was right, while only 16 per cent demurred. And even among pensioners themselves, 55 per cent agreed with the proposal, with only 27 per cent against.

Andy Burnham’s critics are right to point out that much of his rhetoric on Tuesday represented a throwback to the red-in-tooth-and-claw socialism of the 1970s. But they must also recognise the mood of a country that is now desperate for change.

Go into any pub or supermarket, and ask those present what they think of the privatised utility firms. You will not hear a passionate defence of Thatcherite free-market liberalisation. Instead people will spit at the mere mention of their names, demand these companies are renationalised, and call for their executives to be slung in jail.

A similar response will – in many quarters – greet anyone trying to defend Brexit. The word has become synonymous with political betrayal. As Burnham correctly pointed out, the claim that those who backed leaving had ‘taken back control’ of their country is now widely viewed even by a majority of Leave voters, never mind Remainers, as a cruel joke.

Earlier in the week a pollster published a ‘word cloud’ of perceptions of the Prime Minister. Some were positive, others negative. But one stood out: ‘Different’.

An ability to secure the mantle of change is the most desired in modern politics. And Andy Burnham appears to have seized it with both hands. This means the Right are going to need to have a very clear strategy from here.

Reform are all but absenting themselves from the fight. Although a YouGov poll this week showed a modest boost in support, the party remains well down on where it was even a few months ago. Nigel Farage and his lieutenants have decided to fall back on a core vote strategy: one that abandons any pretence of being a serious alternative government, and instead relies on rebranding themselves as a single-issue pressure group focused exclusively on immigration.

Which leaves – as I have written before – Kemi Badenoch as the only realistic alternative to Burnham’s proudly undiluted socialism. In his speech, the Prime Minister presented her with a number of very tempting targets.

A ‘death tax’ on social care. An abandonment of Keir Starmer’s manifesto commitment to protect the triple lock. A trashing of Brexit. A ‘progressive’ gerrymandering of the electoral system.

When she responds in her own speech next week, the Conservatives’ rejuvenated leader needs to avoid falling into the elephant trap Burnham has set for her. Jibes at the Prime Minister for setting out an agenda that would return the nation back to the 1970s have some merit. But at the moment they do not have resonance. And what will be worse is if Badenoch replies with an agenda that is based around taking Britain back to the 1980s.

A ritualistic defence of privatisation. A circling of the wagons around the manifest unaffordability of our current pension settlement. An offhand rejection of Burnham’s accurate critique of the social care system. A full-throated defence of Euroscepticism.

That will definitely endear her to those in her party, and the country, who hanker for some good, old-fashioned, robust Conservatism. But while authenticity is vital to healing the fracture on the Right, she cannot make the mistake of allowing Labour to present itself as the primary agent of change.

The reaction to Burnham’s unprecedented radicalism cannot, in other words, be Tory timidity. Instead, it must be a forward-looking, reforming zeal.

The consultation over complete abolition of inheritance tax must be truncated to allow a clear commitment to the policy next week in Birmingham. Badenoch must also set out how she herself intends to bring the rapacious privatised utilities to heel. And above all, she must unveil a competing vision that shows Conservatism is able to properly embrace the opportunities and confront the challenges of the new millennium, not retreat into a sepia-tinted comfort zone of the previous one.

Andy Burnham tried to set his speech apart from ‘politics as usual’. But in truth it was keenly political. And skilfully so.

‘Andy’s speech was the moment he was able to clearly set out the bold change he’s been promising,’ one aide said.

‘He’s made a clear break with politics as usual.

‘He said before he got to Liverpool that when he left people would not be in any doubt about his plan and his values. And he’s clearly achieved that.’

In response Badenoch’s team believes they have been handed an opening.

‘It was just an attempt to pitch to the Left,’ one shadow minister claimed.

‘And as a result there were huge gaps, especially on the economy. Nothing on growth. Nothing on debt. No evidence Burnham actually appreciates the scale of challenges facing business. And we can exploit that.’

Possibly. But the truth is the Prime Minister has stolen a march on his opponents. The charge there is nothing to Burnhamism but vibes and TikTok videos no longer stands.

He has hurled down the gauntlet to Kemi Badenoch. She must think very, very carefully about how she picks it up.