Inheritance (Provision for Family and Dependants) Act1975. The categories include a child of the deceased.
Melita Jackson chose, in her will, to give some £500,000 to various animal charities. Her daughter (Heather Ilott) has succeeded in the Court of Appeal in obtaining reasonable provision - Telegraph 28th July - Could Your Will be overturned by a court?
The court's judgment is Ilott v Mitson and others  EWCA Civ 797 (Arden. Ryder LJJ and Sir Colin Rimer).
The case has raised a considerable amount of comment in the media.
One example is this Max Hastings article in the Daily Mail 29th July - Who are Judges to tell us who we can leave our money to in or wills? Mr Hastings either does not notice that the judges are applying legislation enacted by our own Parliament or, if he notices, chooses to ignore the fact and lead on to have a crack at "human rights" laws instead. Human Rights are not even mentioned in the court's judgment.
Where an individual dies intestate (that is, without a will) it is still possible for applications to be made under the Act since the law relating to intestacy may not give reasonable financial provision for the applicant.
It is always advisable for those with any significant assets to make a will. Anyone seeking reasonable financial provision against a deceased person's estate is well advised to consult with solicitors who specialise in such claims.