Boris Johnson was pictured leaving Downing Street yesterday for the Commons.
As he waved to cameras, the cuff of his blue shirt was exposed from his jacket.
Eagle-eyed social media users spotted bottom cuff button in the top button hole.
It comes after users claimed Prime Minister was losing hair - a Covid symptom.
Beleaguered Boris Johnson was pictured with his shirt cuffs buttoned-up the wrong way ahead of yesterday's bruising battle with Sir Keir Starmer in the House of Commons.
The Prime Minister's wardrobe gaffe was spotted in a picture taken before yesterday's Prime Minister's Questions - in which he clashed with the Labour leader over the best way to tackle the coronavirus pandemic.
As the Prime Minister waved to the cameras while leaving 10 Downing Street, the cuff of his blue shirt became exposed from the sleeve of his suit jacket.
The picture shows the two-button cuff buttoned the wrong way - with the bottom button put through the top button hole.
Celebrity stylist Lucas Armitage today told MailOnline the gaffe was 'alarming' and said it was time the Prime Minister hired a stylist.
He said: 'We trust the PM to effectively run the country so would hope he could undertake basic tasks we allow children to perform.
‘Seemingly, the man in charge of coordinating a response to a global pandemic can’t even button up a shirt.
‘To say this is alarming is an understatement.'
Mr Armitage added: 'As a stylist and someone living under his leadership, I have grave concerns about Boris, and the way he presents himself is only serving to cement those fears.
‘As Boris has demonstrated, he can’t get dressed himself. I feel he would benefit from some form of dresser or stylist to ensure he doesn’t make the same mistakes in the future and perhaps instill some sort of belief in him as a leader again.’
Social media users were quick to spot the gaffe, with one saying: 'Boris Johnson cannot even do up his shirt cuff buttons right.'
Another added: 'Boris Johnson can't even do up his shirt cuffs correctly...'
It comes days after eagle-eyed TV viewers spotted several strands of blonde hair on the PM's shoulders when he addressed the Commons on Monday.
Some even claimed it was a sign of hair loss - a symptom linked with Covid-19.
Mr Johnson was admitted to hospital in April after testing positive for coronavirus and he spent three nights in intensive care - later revealing he was given 'litres and litres of oxygen' to keep him alive.
Berrio wrote on Twitter: 'Boris's hair falling out now. What’s next?' while Marc Burrows asked: 'Is Boris losing his hair?'
Michael Ball added: 'Is Boris's hair falling out or has he let his dog sit on his jacket?'
Another Twitter user yesterday wrote: 'Looked very much like Boris Johnson is losing his hair in parliament earlier today.
'Jacket was covered in hair. Its a side effect of Covid. Many suffer along with memory issues and brain fog.
Multiple clinics and studies have reported a link between COVID-19 and hair loss among survivors.
Experts say most COVID-19 patients are suffering telogen effluvium (TE), a temporary condition that involves hair shedding, caused by physical or emotional stress, high fever, illness or weight loss of over 20 pounds, according to WebMD.
Dr. Sarah Hogan, a clinical instructor at UCLA says the link between hair loss and the virus makes sense as it often happens to patients three to five months after a stressful illness.
Specialists at the Belgravia Centre in London say they’ve noticed an uptick in TE cases in patients who battled coronavirus.
Dr. Natalie Lambert from the Indiana University School of Medicine conducted a survey along with Survivor Corps among virus 'long haulers' and found over 400 patients out of 1,500 experienced hair loss.
In all, the survey listed 98 symptoms, including lesser-known issues like weight gain, clogged ears, dry eyes and rash
'Considering these issues Covid can cause, are the likes of Johnson and Trump fit to govern?'
In August, a leading clinic reported a link between Covid-19 and hair loss after survivors complained the disease caused their locks to fall out in clumps.
Specialists at the Belgravia Centre in London said they began noticing an uplift in cases of telogen effluvium (TE) - a shedding condition caused by a disturbance in the hair growth cycle - in patients who battled coronavirus.
TE - which sees a high percentage of anagen follicles (follicles which are actively growing hair) go into their resting phase prematurely across the scalp - typically follows a stressful event and is triggered two to four months after, often causing alarm to sufferers.
Other viewers took a lighter take on the PM's appearance.
Gavin Hepworth said: 'Has Boris had a fight with a cat before addressing the nation?Jacket covered in hair and who knows what else.'
Another viewer wrote: 'You'd think Boris Johnson would have at least brushed his hair before addressing the nation over a deadly virus.'
Scott Crawford added: 'Boris's hair leaving his head quicker than the UK from Europe.'
Others asked why no-one noticed the hair before he began his address.
Sukky Choongh wrote: 'You know Boris's staff don't like him! I would never let my boss go on stage with even one stray hair on his collar!
Someone else asked: 'Does no one "check him" before he speaks in the chamber?'
The talk about Mr Johnson's hair came weeks after social media users sparked a debate over whether the Prime Minister was wearing make-up during an address to the nation.
The Prime Minister was mocked on social media for sporting what appeared to be a heavy layer of makeup before going on camera, with some pictures suggesting his hands may have received some cosmetic treatment too.
One user wrote: 'If Boris Johnson had worn any more makeup for this Covid briefing he'd be morphing into Donald Trump, which would be hilarious if it wasn't actually his biggest goal in life.'
But a Downing Street spokesperson denied that he wore make-up on his hands during the TV address, at the end of September.
However, MailOnline's makeup artist expert believes that Mr Johnson may have applied foundation to his hands to match his 'sunkissed' visage.
Olivia Todd, who works with celebrities, said the PM's rigorous hand sanitising routine could have stripped the natural oils from his hands, resulting in redness.
'Boris could be wearing makeup on his hands for a variety of reasons.' Ms Todd told Femail. 'It could be that the excessive washing and hand sanitising over the last few months has taken it's toll, as this strips the skin of oils known as sebum, and causes dehydration. Resulting in hands looking dry, cracked or even inflamed.'
The Hampshire-based makeup artist added: 'Makeup face and body foundations, primers and skin finishers work wonders for faking smooth-looking hands and it looks as though this is what we are seeing here.
'Boris is also looking rather sunkissed and so his hands look as though they've been made to match his radiant complexion.'
However, when MailOnline asked if the premier had applied makeup to his hands, a No10 spokesman said: 'No.'