A mum kicked her grown-up son out of her home in a legal row over who is allowed to live in the property.
Elizabeth Ashley, 79, changed the locks on the £1.2 million house to prevent her son Mitchim, 53, returning home two years ago.
Mitchim is now appealing to the courts to allow him to live in the house where he grew up.
If his wishes aren't granted, he wants his mother to be forced to sell up and give him half the profits.
However, Elizabath claims her son has harassed her and is counter-claiming for him to pay her damages.
The extraordinary saga centres around a terraced property in Wandsworth, south west London.
It was rented by Elizabeth for 40 years on a secure tenancy until she and Mitchim bought it in 2001 for £200,000 – about £1 million less than its current value.
Central London county court heard that Michael paid more than £150,000 of the purchase price in cash.
He also acted as guarantor for a £45,000 mortgage in his mother's name, covering the rest of the cost, with her contributing £5,000.
Mitchim claims it's unfair that his mother refuses to let him live in his childhood home, particularly because he provided most of the funds for the purchase.
A deed of trust was drawn up between mother and son at the time of the purchase, setting out that they each owned half the house and also detailing rights of occupancy, the court heard.
Mitchim's lawyer Joshua Swirsky told Judge Diana Faber: "The mother is being unreasonable in excluding her son. The trigger for the litigation was Mrs Ashley's decision to change the locks to the property when her son said he wanted to spend more time there.
"The purpose of the trust was to provide a home for Mr Ashley, as well as Mrs Ashley, and he indeed occupied the property between 2001 and his exclusion in 2012."
Criticising Elizabeth's 'unreasonable refusal to allow him to resume occupation', Mr Swirsky told the judge that, in the event that it is impossible for Mitchim to return to the house, his client wants it sold and the proceeds split.
He said: "If the unreasonable attitude of his mother means it is impossible for him to live at the property, the purpose for which the trust was created has come to an end and the court can make an order for sale.
"She has lived there a long time and raised children there, but this is a situation where there is over £1 million of equity in the property, and each occupier would be entitled to at least £500,000 on sale.
"That should be enough to accommodate two people separately, even in London in 2014."
But Elizabeth's lawyer David Hyde said his client was within her rights in banning her son from the house.
Mr Hyde said: "There is evidence that Mr Ashley allowed strangers into the house as lodgers."
The barrister argued that Mitchim has no right to occupy the house under the trust deed, and that his mother was entitled to exclude him.
Mr Swirsky spoke about the claims that his client had harassed his mother, saying: "The allegations consist of a number of telephone calls, a single instance of unspecified abuse in person, and a malicious call to the RSPCA."
Judge Faber will give her decision at a later date.