Margaret Baverstock, who was so unwell she could "barely flicker an eyelid", signed a will at the age of 76 in March 2021 that excluded her son John Baverstock and left everything to her daughter Lisa.

Lisa Baverstock held and "propelled" her mother's pen hand as she signed over her entire fortune on her deathbed - and a judge has now declared the will invalid.

When Margaret passed away eight days later, John, now 61, received nothing from her estate, which included her house in Guernsey Grove, Herne Hill, south London, all of which went to his now 55 year old sister. John contested the will in court, arguing that a video of the signing demonstrated it was not an independent act by his mother but rather she was coerced by Lisa into a charade of due execution of a document she did not understand.

After viewing the footage of Lisa directing her mother's hand, a judge declared the will invalid and awarded John half of his mother's money. Judge Jane Evans-Gordon ruled that Margaret "had no idea what was going on" when the document was signed, thus rendering the will void.

During the trial, the Central London County Court heard that Margaret had been diagnosed with dementia. The judge determined that Margaret, who was suffering from advanced dementia, arthritis and suspected lung congestion, was incapable of signing her name or understanding what she was being asked to sign.

John, an electrical compliance manager, challenged his mother's will after being excluded from it. His mother, who was diagnosed with dementia in 2014, made her last will just eight days before her death in March 2021.

John alleges that his sister Lisa, who moved into their mother's home to provide care in 2019, had grown increasingly resentful towards him and effectively barred him from their mother's house. After discovering he had been left out of the will, John contested it on the grounds that his mother was too mentally frail to comprehend what she was doing or signing.

Videos of the will being signed, provided by Lisa for the court, raised questions about its legitimacy, showing their terminally ill mother struggling to give her final testament. The footage revealed that former care worker Margaret could only respond to basic questions by saying "yeah" or grunting.

John's barrister, Mark Jones, described how Lisa repeatedly tried to put a pen in her mother's right hand so she could hold or grip it. "She finally placed a pen between her fingers and placed first her right hand and then her left hand over the deceased's hand," he said.

He explained that "By force and motion of her own left hand," she guided her mother's writing hand to mark the will. The will itself was a homemade document drafted by Lisa from an online template, naming her as Margaret's executor and sole beneficiary.

John claimed that his sister had become increasingly suspicious and resentful towards him.

In February 2021, a dispute erupted at the family home. The trigger for the argument was Lisa's concern that "someone was trying to sell the property without her knowledge", according to her brother's lawyer.

"Lisa threatened to call the police if John would not return the house keys and leave the property, which he did without further demur," said Mr Jones.

"John speculates, ex post facto, as to whether this was manufactured by Lisa to seek to exclude and discredit him in his late mother's eyes."

However, Lisa, a former coach driver who represented herself in court, claimed her mother had been adamant that she should inherit her home.

She insisted her mother wanted the will drafted to reflect her wishes and was fully "compos mentis" at the time. Lisa said she sacrificed everything to care for her mother around the clock, alleging that she had pleaded with her brother "crying on the phone to come down and give me respite".

She maintained that from 2017 onwards, John "could not be bothered" with their mum. "As to the will, it was basically how my mother wanted her wishes done," Lisa told the court.

"She didn't want my brother to inherit anything and made that perfectly clear to me over the course of the years."

John, however, insisted that he did his utmost to see and help out their mum - "visiting her regularly, weekly or fortnightly" until his sister effectively shut him out.

When Lisa questioned her brother in the witness box, asking: "Do you recall mum telling you to get out of the house?" he responded: "I don't recall that, the only person who tried to get me out of the house was my sister - you."

The judge, declaring the will invalid, noted that the video showed Margaret barely able to "flicker an eyelid" as one of the witnesses read the contents of the document, adding that the pensioner did not read the document herself.

"She could not sign it herself because she was unable to hold the pen or move her hand to write her name," the judge said. "Lisa manipulated her hand and herself physically caused the deceased's hand to move and make marks on the document.

Referring to the video transcript, the judge observed: "while doing this Lisa says to the deceased: 'ready Mum, do you agree to this?

"There's no response and Lisa says again to her mum - ok? And the deceased responds 'yeah'."

During the trial, Lisa insisted that her mother was still mentally capable when she signed her will and denied that she had dementia. Despite being very frail, Margaret - who Lisa said "died in her arms" - was still able to engage with the world around her, to "enjoy a laugh and a joke".

The judge pointed out that the deceased was unable to hold the pen due to her contractions.

"Lisa Baverstock physically manhandled the pen into her hand," she told the court, adding that Margaret's eventual signature "bore no resemblance" to a 2017 example of her genuine signature.

The judge said : "I am satisfied that the deceased had no idea what was going on. She was unable to act independently and, although she responded with a 'yeah' or even a grunt when addressed as mum, that was simply a response to being directly addressed and didn't indicate consent to signing the will or acknowledging its contents.

She added that Margaret looked "completely blank" during the reading of the will and only responded to her daughter.

"At no point did Margaret ask Lisa for help in signing the will or direct her to sign the will on her behalf. Nobody ensured that she understood what was happening by asking her questions about the contents of the will or asking her to tell them her wishes, and she cannot fairly be said to have signed the will."

In addition to finding that the will wasn't properly executed, the judge determined that Margaret lacked the necessary "testamentary capacity" and didn't "know and approve" the contents of the will.

The judge concluded: "The deceased was also extremely frail and on her deathbed. In these circumstances, it was necessary to question Margaret to ensure her understanding.

"Merely reading out the document and asking if she understood it was not enough."

The judge ruled that Margaret Baverstock died "intestate," due to the absence of any other known will. This means her £700,000 assets must now be equally divided between her brother and sister.

However, Lisa is also required to cover John's legal fees, which are estimated to be up to £80,000.