The Supreme Court will today hear a case that should clarify the law on challenging wills on the grounds that they do not make reasonable provision. Animal charities are appealing a Court of Appeal decision in July last year in favour of Heather Ilott, who had been excluded from her mother Melita Jackson’s will.

Jackson left her estate, worth around £500,000, to charities. She had excluded her daughter after she left home with a boyfriend as a 17-year-old.

In the initial hearing, the High Court awarded Ilott £50,000. Both parties appealed: Ilot claimed she had not been awarded enough while the charities said it was too much. On appeal, Ilott, who is in her fifties, was awarded £143,000 - to buy the rented home she was living in - plus an extra £20,000 for additional income.

The Court of Appeal said Ilott, who has five children and was on benefits and without a pension, was not given a reasonable provision in the will.

The appeal in Ilott v Blue Cross and Ors, filed by the Blue Cross, the Royal Society for the Protection of Birds and the Royal Society for the Prevention of Cruelty to Animals, will ask whether the appeal court was wrong to set aside the initial award and to allow Ilott to preserve her entitlement to state benefits.

Paula Myers, head of the wills, trust and estate disputes team at UK firm Irwin Mitchell, said: ‘The ruling potentially made it easier for adult children who have been left out of wills to challenge them if they have not been left a reasonable provision and we have seen a rise in enquiries from people who feel that they have been unfairly disinherited.

‘Whatever the Supreme Court decides, the judgment from this case will provide clarity to the Inheritance Act 1975 and likely set out the guidelines for when challenges can be brought to wills based on inadequate provision and set out the criteria which must be met in order to disinherit your adult children,’ she added.