The new Defence Secretary was 'missing in action' on Friday as Labour's military woes descended into farce.

After being parachuted into the top role, former airborne officer Dan Jarvis kept a low profile on his first day replacing John Healey, who quit on Thursday with a blast at defence spending plans.

Mr Jarvis was kept away from any awkward questions, with the media banned from the opening of a drone factory they had previously been invited to.

But the fallout from the Defence Investment Plan continued as Washington told Britain it must do more.

Friday was supposed to see Keir Starmer cut the ribbon on the drone centre just off the M4.

The opening had already been delayed by four months due to Downing Street dithering over defence cash.

As it became clear the long-awaited DIP was not going to be launched as planned this week, Mr Healey was set to address the workforce and leaders of industry.

But those plans collapsed with his explosive resignation as he was told to swallow future real-term funding for the military of just £10billion over four years, only a third of what is required.

On Friday, with the under-fire PM hunkered down inside Downing Street, Mr Jarvis was dispatched to the drone site, arriving late and leaving earlier than expected, having been in the job only since 9pm the previous day.

There was no opportunity for him to be asked how he can stomach a plan others have declared 'dead on arrival'.

Last night, shadow Armed Forces minister Mark Francois said: 'Jarvis has opened his account as Defence Secretary with a stealth visit to a drone factory.

'He may find it more difficult to avoid the media if his second action is to surrender to the Treasury and the PM over the long-delayed but clearly underfunded Defence Investment Plan in a way which John Healey was obviously unwilling to do.'

As Mr Healey won plaudits from around the world for his principled stance, Mr Jarvis told representatives from 30 companies there were 'significant challenges ahead' for the UK defence industry but also 'great opportunities'.

One source in the room said: 'Nobody wanted to mention the chaos of previous days.

'He's got his work cut out. We've waited so long for the Defence Investment Plan and from what we're hearing it's not fit for purpose anyway. Everyone is wondering where we go from here?

'The situation could scarcely be worse. People are struggling to know what to think. It's moved from frustrating to farcical.'

Writing in the Daily Mail, former Armed Forces minister Al Carns, who also quit on Thursday evening, presents a withering critique of the DIP, saying it commits Britain to wasting billions of pounds on obsolete equipment that would be reduced to smouldering wreckage on the battlefield should this country engage in direct warfare with Russia.

As he struggled to fend off mounting attacks that he had bowed to the will of Chancellor Rachel Reeves, Sir Keir insisted yesterday that defence was his 'number one priority'.

In a defiant interview, the Prime Minister claimed he had made 'hard-edged' decisions to fund the DIP that involved raiding every single Whitehall department's budgets, despite Energy Secretary Ed Miliband reportedly refusing.

Sir Keir told the BBC: 'What I'm not doing is taking out day-to-day spending because I'm not prepared to cut our public services. But every department is contributing to this.'

Asked why the soaring welfare budget was not being targeted for cuts, the PM said his Government was focused on 'getting people into work' which will in turn 'free up resources'.

He indicated that the DIP will no longer be published before he heads to the G7 summit with world leaders, including President Trump, on Monday.

'It will be published before the Nato summit, which is a matter of a few weeks away,' Sir Keir said.

Sources said Mr Jarvis, who discussed the plan with the PM and Chief of Defence Staff Sir Richard Knighton in No 10 yesterday morning, would be given time to run the rule over the proposals rather than being bounced into approving it just hours into the role.

Downing Street insisted that defence spending would reach 2.6 per cent of GDP next year and 3.5 per cent, the new Nato target, by 2035.

In his resignation letter, Mr Healey said the deal amounted to a rise of just 0.08 per cent by the end of the decade.

More pressure came from the Pentagon on Friday.

On social media, US Under-Secretary of Defense Elbridge Colby said: 'There is again a great need for more British military strength at this critical time. We urge the UK to meet that need with urgency, scale and determination.

'Our purpose must now be to build our military strength individually and together, and to restore our home fronts that can, once again, supply overwhelming superiority in weapons and munitions.'

Shadow housing secretary James Cleverly – a former home and foreign secretary – said: 'I like Dan Jarvis but I cannot see how he speaks with allies at Nato next week with any credibility.

'Healey and Carns said publicly what everyone was saying privately, Starmer and Reeves don't take defence seriously. A reshuffle doesn't hide that truth.'

And former UK Army commander in Afghanistan Colonel Richard Kemp asked: 'Why did Jarvis agree to drink from Starmer's poisoned chalice? It is a betrayal giving apparent legitimacy to a DIP that puts the country into great danger.

'Like any former military MP he should have turned down the job. He should understand the gravity of the situation. Ex-military MPs have a duty to press Starmer. The same applies to the service chiefs.'

Former top mandarins also urged the Government to rip up the DIP in the wake of Mr Healey's shock resignation.

Former Cabinet Secretary Lord Sedwill said: 'Dan Jarvis might have to live with the budget total Healey and Carns couldn't accept. But he must rewrite the Defence Investment Plan to transform defence and make the tough choices we need.'

And Lord Ricketts, Joint Intelligence Committee chairman under Tony Blair, said: 'How can he credibly sell a plan which his far more experienced predecessor condemned as increasing the risk to personnel and making the country less safe?'

Labour leadership hopeful Wes Streeting questioned Sir Keir's focus, writing on social media: 'Growth was meant to be the number one priority, is it still?

'There's not enough money for defence, but today the Government announced £4.5billion for walking and cycling. Make choices. Decide. Lead.'