It can be a complicated area, this.
To quote from a previous q:
Under the rules of intestacy, if a surviving spouse has children and the Estate is valued as greater than �125,000 then the spouse is entitled to the first �125,000, all of the personal belongings, and a life interest in half of the remainder.
The Executors must invest that half share in Trust, in which the surviving spouse has a life interest, which means that the income from this Trust will be paid to the spouse until his/her death.
On the death of the spouse the capital (i.e. the original half share) will be divided equally between the children.
The other half share of the Estate will be split equally between the children
So, if your father dies first, you might not get the property. You'd be a lot safer getting your father (& wife) to make wills.