Boris Johnson’s “go back to the office” edict is facing fresh humiliation after it emerged that key civil servants have been advised to bring lunch from home to avoid eating out near their workplace.

HuffPost UK can reveal that staff based at the Home Office’s HQ in Marsham Street, London, have been emailed a presentation which appears to directly contradict the PM’s own campaign to help eateries like Pret a Manger and other retailers.

The presentation, complete with a picture of a water bottle and a sandwich, stated: “bring food and drink from home to prevent having to go to shops and stores”.

One insider said that staff were also advised to avoid using the lifts in the building at lunchtime, when most staff normally leave the building to grab a bite to eat or a coffee nearby, as social distancing restrictions meant that there would be big queues. “Which won’t help Pret!” they added.

A quiet retreat from the “go to work if you can” guidance could accompany the new coronavirus restrictions expected to be confirmed on Tuesday, when the PM addresses the House of Commons before making a televised address to the nation at 8pm

One of Johnson’s central arguments for a return to office life was to rescue cafes, takeaways and other businesses that have been crippled by the empty city centre streets at the height of the pandemic.

Chancellor Rishi Sunak’s Eat Out To Help Out campaign fo half price meals, subsidised by the state throughout August, was also aimed at reviving restaurants near workplaces.

But with many staff preferring to work remotely for both their health and efficiency reasons, Johnson’s drive to get civil servants to lead by example has so far failed to achieve the success he wanted, and is well short of the 80% target mooted by some in government.

During the early phase of the virus’s spread, the government actively encouraged people to work from home, but Johnson changed that in July to instead say the preference was for a return to the office where possible.

Earlier this month, ministers faced a backlash when it was reported that a new ‘Back to The Office’ PR campaign could see home workers threatened with losing their jobs. Other mooted threats were the axeing of ‘London weighting’ for staff who normally commuted to work but worked remotely.

Ministers such as Rishi Sunak, Michael Gove and Liz Truss have all been snapped coming out of Pret A Manger cafes as they sought to send a message of support for city centre cafes.

Dave Penman, head of the First Division Association trade union that represents civil servants, said: “It can come as no surprise that the government’s approach of setting arbitrary targets for civil servants returning to workplaces was never going to work once it was confronted by reality.

“The decision taken by ministers to set targets for thousands to return to offices ignored both the evidence that many staff were working effectively from home and that sensible plans for gradual returns were already being implemented across the service.

“Instead, ministers wanted a headline with little regard for the practicalities of what they were proposing. It’s all the more ironic, therefore, that a misplaced, tokenistic policy dreamt up around the cabinet table would also fail to deliver on its principle objective of stimulating the lunchtime economy.

“Now with infection rates rising and with the impracticalities of their targets clear for all to see, perhaps ministers will recognise that rather than micromanaging the civil service to virtue signal to the wider economy, they’d be better off leaving it to get on with its job of delivering vital public services.”

Layla Moran, Lib Dem MP and chair of the all-party parliamentary group on coronavirus, said the Home Office guidance to staff underlined the confusion of the government policy

“The gulf between the Prime Minister’s rhetoric and reality is growing by the day. This is completely contradictory – on the one hand the PM is trying to almost force civil servants to work from the office, and on the other hand departments are clearly concerned about the impact of this. How can it be to support businesses if people are being told to bring in food from home?” she said.

“It’s wrong to force anyone to work in the office if they don’t want to – I hope the PM changes his mind and stops pressuring public servants and others to take risks if they don’t want to.

“With a likely second wave on the near horizon, this Government really needs to stop setting such a bad example.”

Ministers had appeared divided over the policy, with health secretary Matt Hancock saying that the location of his staff was not as important as what they did.

“What I care about is that people perform. Of the people I work with, some have been working from home, some come in… What matters to me is that they deliver,” he told Times Radio earlier this month.

A Home Office spokesperson refused to comment on the ‘bring your lunch’ presentation, but said in a statement: “We are doing all we can to ensure our staff can return to our workplaces safely and in line with Covid secure guidance.

“Staff are not prevented from leaving or entering the building if they wish to do so during their day.”