ANT McPartlin’s ex-wife has been ordered to stop attacking his new lover on social media.

Lisa Armstrong was hit with a legal warning after liking tweets accusing ex-PA Anne-Marie Corbett of being a backstabber.

Lawyers say Anne-Marie Corbett was distressed by the attacks, which branded her a “gold digger”, “backstabber” and “second best”.

Ant’s former missus Lisa Armstrong, who he divorced at the High Court last week, is said to be furious at the legal warning which orders her to stop “liking” and retweeting critical comments.

She blames the TV star for being behind it as relations between the trio hit an all-time low.

A source said last night: “It’s getting increasingly bitter.

“After everything Lisa has been through she feels so angry and hurt.

"Lisa was at a very low point earlier in the summer when she realised their marriage was over and felt betrayed when Ant admitted he was in a relationship with Anne-Marie, who she thought was her friend.

“She was inundated with supportive comments on social media.

“She liked some posts but she didn’t expect a legal warning.

“Lisa feels Ant must have been behind the warning, or at least have knowledge of it, and feels very let down by him.”

The Sun on Sunday revealed in June that Ant had started dating mum-of-two Anne-Marie, their former personal assistant.

That month Lisa tweeted a broken heart emoji and said of Anne-Marie: “Yeah My Friend and OUR PA who I let into OUR home.”

A Twitter user, Katherine, quoted Lisa and wrote: “Most men are the same and there are gold digging hoes everywhere to take up the opportunity when they want to stray.”

Lisa liked that tweet, and another saying: “Been where you are and it’s a whirlwind of emotions. Nothing like being stabbed in the back by ppl close to you.”

A tweet she liked in August read: “You will never need a man to define you. Know your worth.

"He swapped steak for luncheon meat and no matter who he ends up with they’ll always be second best.”

Another read: “Look at the reality of the situation. Your ex husband is an alcoholic. His problem to sort out.

"Why do you want someone who lives in denial. His new girlfriend is a filler, nothing more, nothing less, and a distraction from the root of his issues. You’re better off.”

And one posted earlier this month said: “Me and hub are so supportive of you. Giving yr trust to a PA who has ripped your heart out: karma sweetie.”

Ant is fiercely protective of Anne-Marie, who he calls Amsy. She split from her husband last October.

On Friday the couple were seen hand-in-hand at Heathrow after a short break in his native Newcastle.

Strictly make-up artist Lisa, 41, has also told pals that despite agreeing to divorce last week she is not happy with the financial settlement.

She says Ant, 42, has offered their £6million West London home and £1million cash.

Divorce lawyers reckon Lisa can expect to be paid up to half of his fortune and potentially a percentage of any future earnings.

Accountants are carefully probing Ant’s finances.

But sources say he is not worth anywhere near the £62million previously reported.

And they say only his past earnings will be taken into account when splitting his fortune.

Sources also say Lisa has made fresh claims about why she found him “intolerable to live with”, which was cited in their decree nisi.

Ant admitted adultery to speed up the process.

But he insists he started dating Anne-Marie only after he and Lisa had separated.

The source added: “There doesn’t seem an end in sight.

“Ant has only ever made one offer — the house and £1million.

“Lisa feels it is derisory considering his personal fortune and her contribution.

"And the last thing she wants is to stay in the marital home.

Her plan is to sell it and find a new house.

“If she feels cheated on the financial settlement Lisa will want the world to know what happened in their marriage.

“She won’t be silenced, not at any price.

"She’s refused to sign a non-disclosure agreement.”

The former couple now face a six-week arbitration period in a bid to reach a settlement on money and personal possessions.

They are also at war over labrador Hurley and are expected to continue sharing him week by week.

But handovers have caused tension.

In one call about picking up Hurley, Lisa’s dad grabbed the phone and told Ant never to speak his daughter like that again.

A source close to Ant said: “The first major bone of contention has been what to do with Hurley.

“Ant would rather lose his fortune and see Hurley, than keep every penny and lose the dog.”

Lisa has changed the locks on their former home to prevent Ant from letting himself in.

The pair are also at loggerheads over Banksy paintings they own and her jewellery collection.

Ant and Lisa’s split in January shocked the showbiz world.

They had dated for 11 years before Ant proposed in Dubai in 2005.

The following year they wed in Taplow, Bucks, with Ant’s co-star Declan Donnelly as best man.

But the marriage hit trouble in recent years over their apparent struggles to start a family and Ant’s stints in rehab for painkiller and booze addictions.

In March he was charged with drink-driving after a car smash.

He was fined £86,000 and given a 20-month road ban.

He has since shelved TV work and is only due to return when Britain’s Got Talent starts filming in the New Year.