"I wonder if Caroline Dinenage is related to Fred Dinenage?" (Answer turns out to be yes)
Then something plausible sounding but unlikely;
"I wonder if Daniel Kawczynski is related to Jarosław Kaczyński?"
"I wonder if Keith Simpson is related to Homer Simpson?"
Then all bets are off, with bonus points awarded for surrealism.
"I wonder if Mark Spencer is related to Marks and Spencer?"
"I wonder if Norman Lamb is related to a lamb?"
"I wonder if Louise Bagshawe is related to Bagpuss?"
"I wonder if John Mann is related to the Mister Men?"
"I wonder if William Hague is related to the International Criminal Court at The Hague?"
You can join in if you like. http://www.theyworkforyou.com/mps/