Mum died four years ago and her estate was left to myself and my siblings. Dad instigated a "Deed of variation" to pass all the assets to him rather than to us so that he could do some clever inheritance tax planning. We duly signed it. He then met a new woman, literally weeks later, and the fall out from that has been awful. None of us are ready to accept her and as a result we are struggling to keep things pleasant between us. If dad dies, and he chooses to leave all of his estate to her, can we claim the part we signed away, mums part ? None of us sought legal advice when we signed that deed, and never foresaw this happening.