A source close to the couple said the surprise split had ‘come out of the blue’.
But a friend said that the end of their three-year relationship had been amicable and that the former couple would remain friends.
Lisa, 46, used to regularly post selfies on Instagram of her looking loved up with James, along with images of them enjoying a series of luxury holidays.
But following their break-up, nearly three weeks ago, she has made no mention of James and has instead been posting pictures of her ten-year-old Labrador, Hurley.
Ant McPartlin’s ex-wife Lisa Armstrong (left) split from her boyfriend James Green (right) who has moved out of her home
Ant McPartlin and Lisa Armstrong at their wedding at St Nicolas Church in Taplow, Buckinghamshire on July 22, 2006
Lisa, 46, used to regularly post selfie pictures on Instagram of her looking loved up with James, along with images of them enjoying a series of luxury holidays
The source said: ‘I don’t really know what has gone wrong. The two of them were only on a swanky holiday together in the Caribbean or somewhere about eight weeks ago.
‘He was with her one day, and he just wasn’t with her the next day. There was no inkling that anything was wrong.’
Lisa started dating father-of-two James in 2020 when he was estranged from his wife Kirsty after moving out of their marital home in Hampshire.
He helped her find love again after her split in 2018 from her husband, Ant, famed for his double act with co-presenter Dec Donnelly.
Lisa, who married Ant in 2006, was reported in January 2020 to have received £31m as part of a divorce settlement with her famous Geordie ex-husband.
But she took to Twitter to dismiss the claims, posting a message saying: ‘Nope a load of nonsense AGAIN….’
Lisa also reportedly kept the former £5m home in west London which she once shared with the I’m a Celebrity presenter and host of Ant & Dec’s Saturday Night Takeaway.
A source close to the makeup artist says she was away on a business trip when James told her that he was ending their three year relationship
Lisa (right of right photo) started dating father-of-two James (left; left of right photo) in 2020 when he was estranged from his wife Kirsty after moving out of their marital home in Hampshire
Whatever the terms of her divorce, she was able to snap up a new five bedroom riverside home in Chiswick for £3.85m in September 2020.
She wasted no time in putting in a planning application for a range of improvements including a swimming pool, gym, pergola, gazebo and a summer house.
Lisa was pictured for the first time with James in August 2020 when they looked blissfully happy together on an outing in a London park just months after her divorce was finalised.
The pair were snapped engrossed in conversation on a bench while sipping Lucozade and beer.
James’ estranged wife Kirsty told at the time of her shock at waking up to see the photos on the morning of her 36th birthday.
But Kirsty, who had been married to James for five years, admitted she had suspected he was in a relationship with Lisa after being tipped off by a friend.
James – who worked at the time for a company installing electric doors – was said to have earlier moved out of his £475,000 family home in Winchester, Hampshire.
He reportedly met Lisa before the Covid pandemic, but they started seeing each other properly when lockdown restrictions eased.
Lisa’s recent posts on Instagram make no mention of James. Her last two posts feature a picture of her ten-year-old pet Hurley taking a nap and a video of the pooch fixating on a tennis ball.
The picture is captioned, ‘The sleeping baby, next to his Mama!!!…#Hurley #Mamasbabyboy’ while a post on the video says, ‘Oh Hurls, you’re too funny!!!’
Lisa last mentioned James on Instagram five-weeks-ago when she posted a picture of a bunch of flowers he had apparently given her. An accompanying message, visible to her 156,000 followers, said: ‘Thank you my gorgeous boy’.
The message which was accompanied by nine love heart emojis tagged in his Instagram account which has since been taken down.
Lisa (pictured) split from TV presenter Ant, 47, in 2018 following a 12-year marriage, and he is now remarried to Anne-Marie Corbett
Lisa was living it up with her electrician boyfriend James Green (pictured) before their split
Lisa pictured with her former husband TV presenter Ant McPartlin, 47, in 2015
A week earlier, she posted a selfie of them together with six love hearts, and a few days before that she put up an image of them at a waterside location with the caption: ‘River nights with my one’.
Three months ago, Lisa posted a picture of James, dressed casually in a lumberjack shirt and holding a cocktail.
The image was captioned with the words: ‘Date night with my gorgeous boy #Myfav #myhappyplace. Love you so much!!’
Another series of pictures celebrating his 40th birthday 18 weeks ago showed James with a display of red and white balloons, enjoying a beer and with Lisa beside a hotel pool while on a romantic break.
An accompanying message stated: ‘Happy Birthday to my gorgeous boy. Welcome to the naughty forty’s (sic)!!! Have the best day, love you millions.’
Lisa first met Ant on a Smash Hits tour in Newcastle in 1994 when she was in a band called Deuce which performed alongside him and partner Dec who were reaching new TV and music heights as PJ & Duncan following their stint on Byker Grove.
They were together for over ten years before Ant proposed to her on holiday in Dubai in 2005, and they married at a country house hotel in Buckinghamshire in July 2006 with Dec as Ant’s best man.
Lisa retrained as a makeup artist, ultimately working her way up to become head of makeup and hair for BBC’s Strictly Come Dancing.
Ant spoke in 2013 about his struggles to conceive with his wife, telling Radio Times: ‘Lisa and I would love to have kids. We’re trying. It’s tougher than you think when you get a bit older.’
He also told Fabulous Magazine: ‘I think I’m lucky. Lisa works in the industry and understands it. She’s constantly working – sometimes more than me!
‘We would love to have a family so fingers crossed. If we’re blessed with children, then we’d be over the moon!’
Ant went into rehab for alcohol and prescription drug addiction in 2017 when he admitted that he needed help, saying: ‘I feel like I have let a lot of people down and for that I’m truly sorry.’
He claimed in an interview that he had put Lisa through hell with his mood swings and depression, but praised her for being ‘fantastic’.
Ant, who lives in a £6m mansion in Wimbledon, south west London, married his former personal assistant Anne-Marie Corbett, 46, in a church ceremony in August 2021 in Heckfield, Hampshire
Rumours that the couple had split emerged in autumn 2017 after Lisa did not accompany Ant to Australia for I’m A Celeb.
She denied there were problems at the time, pointing out that she had a job and had not been to Australia for years.
But Ant’s representative announced in January 2018 that the couple’s 11 year marriage had ended.
Ant began to be linked with his personal assistant Anne-Marie Corbett just weeks later in March 2018.
Lisa was said to have indicated her disapproval of the relationship by liking a fan’s tweet which said it was ‘a major girl code breach’ to ‘start shacking up with your wife’s friend’.
Her and Ant’s marriage officially ended in October 2018 when she was granted a decree nisi after he admitted adultery.
But the pair continued finalising their financial settlement while reportedly disagreeing over custody arrangements for their labrador Hurley.
During their divorce battle, Ant is said to have told lawyers: ‘She can have anything she wants – except the dog.’
The former couple reportedly agreed to take it in turns to look after Hurley.
The arrangement led to the TV presenter’s chauffeur ferrying the dog between the two of them so they did not have to see each other.
It was reported in February this year that Lisa wanted her pet to live with her full time.
She is said to have argued that it was only fair as Ant also had two maltipoo dogs – Maltese and poodle crossbreeds – called Milo and Bumble.
Ant, who lives in a £6m mansion in Wimbledon, south west London, married Anne-Marie, now 46, in a church ceremony in August 2021 in Heckfield, Hampshire.