What to do? Imagine that you're an ambutious MP in a very, very marginal seat. You're a Sikh in a city with the second-highest Sikh population in the UK, and you reckon there's a solid Conservative and conservative potential vote there (sadly mistaken: the voters are more sophisticated than that).
But you also have a reputation for slavish loyalty. You've never, ever expressed an opinion contrary to the views of the party leadership, nor voted against them.
But now that leadership is asking you to vote yes to equal marriage. At long last you've found an actual principle. Library closures haven't bothered you. Cuts to disabled children's benefits you voted for without a twinge. You've cheered on bombings, renditions, recessions, sickenings and thickenings in the Health and Education sectors.
But now you've discovered that you hate the gays.
What's a man to do? Please your imaginary homophobic electorate in the hope it will save your worthless skin? Or vote with the leadership to get your well-padded bottom on the House of Lords' read leather seats after the 2015 Meltdown?
I guess we'll find out which way Paul Uppal votes this afternoon. In the meantime… place your bets.