There’s a chill in the air. Not from the changing seasons – it’s still fairly balmy – but from the latest attempts to orchestrate a subtle psychological manipulation of us all.

About 18 months ago, in the lockdown summer of 2020, I started to argue that the Government’s response to Covid is driven not so much by medical science or epidemiology, but instead by the psychological insights of behavioural scientists. In my book, A State of Fear: How the UK Government Weaponised Fear During the Covid-19 Pandemic, I argue that controversial “nudge theory” lies at the heart of Westminster’s response. It refers to sneaky attempts to prime, prepare and prod us into their desired mindset and course of action, without us ever realising we are being coerced.

Some responses to my book seemed naive. Many believed that Downing Street’s approach was genuinely grounded in public health epidemiology. Now, I think the dial is starting to move; the Government’s strategy becomes ever-more clear. Once nudge is seen, it can’t be unseen. Behavioural scientists were dazzling the public with card tricks. This week, the Government may have overplayed its hand.

On Tuesday, Professor Neil Ferguson, the Imperial College epidemiologist whose modelling was used as the basis for the UK’s lockdown policy, made an illuminating comment on BBC Radio 4’s Today programme. “Nobody likes having their freedoms curtailed by measures but it’s prudent to be cautious, in everyday interactions certainly,” he told presenter Sarah Smith, “and wearing masks certainly helps that: it reminds people we’re not completely out of the woods yet.”

It was a startling admission, if we needed one, that masks are as much about psychology as they are about preventing infection. They act as a social cue, to use the language of behavioural scientists, nudging us into vigilance.

Then, on Wednesday, after NHS leaders urged the Government to implement its Covid ‘Plan B’ immediately (including the reimplementation of mandatory masks in crowded indoor spaces, and advice to work from home), business secretary Kwasi Kwarteng took to television to herald the “hard-won gains” Britain has eked out of lockdown, adding: “I don’t want to reverse back to a situation where we have lockdowns, I don’t think it’s necessary”. It was a deployment of the sunk-cost fallacy: we’ve come so far, we mustn’t allow our good work to be undone. Until hearing Kwarteng’s words, you mightn’t have known there was even a risk of another lockdown. But now the idea has been seeded in your mind, ever so subtly.

Yesterday, the Health Secretary Sajid Javid gave the first Downing Street briefing in a month – surely a portentous sign in itself… – in which he announced that Covid infections had risen 15 per cent in a week, and warned that cases could hit 100,000 a day this winter.

But, he continued, “if we all play our part, then we can give ourselves the best possible chance in this race… [We can] get through this winter and enjoy Christmas with our loved ones.”

Why is Christmas even in doubt, an alarmed listener might think?

These psychological cues are carefully calibrated, more so than many realise. In a document drawn up by the “Nudge Unit” (known formally as the Behavioural Insights Team, a team seat up by David Cameron in 2010; it is now a private company, but is still one-third owned by the Cabinet Office), scientists examine the success of Slovakia’s mass testing programme, looking at how we could replicate that success in the UK.

“Use empowering messaging,” the document advises. “Motivate people by creating a spirit of national resistance to the virus, highlighting the ability to make a positive action and contribute to the national effort to save lives and livelihoods. Use ‘save Christmas’ messaging.”