Not sure if this belongs in CS or IMHO.
It is the late 19th Century.
John Clayton, Viscount Greystoke, disappears.
While missing, his son and heir, John Junior, is born.
One day, the child is playing with his father’s inkwell, and gets handprints on a page of the father’s diary. John Sr writes about the incident, and records the owner of the fingerprints.
John Sr dies. John Jr grows up to be Tarzan of the Apes.
20 years pass. John Sr’s body is discovered, along with a skeleton erroneously assumed to be John Jr. The father is now known to be dead, and the son is believed to be dead. The peerage of Greystoke passes to a cousin, William Cecil Clayton.
A couple of years later, John Junior is revealed to be alive, and fingerprints prove his identity. On his deathbed, William confesses that he had eventually learned that Tarzan was the legitimate heir to the peerage.
During the years when John Sr was missing, and John Jr was unknown, could William have had him legally declared dead, and taken the seat in the House of Lords, and voted on legislation?
During the years when John Jr was believed to be dead, I presume William could have sat in Parliament and voted on legislation. When John Jr’s existence and identity were revealed, would this affect the validity of any legislation on which William had voted? If a bill had passed by a single vote, could the opposition overturn the law?