At the end I stuck to my principles (see the Archive, around about August 2004, I expect).
As a disbeliever in civil marriage, I had to destroy the envelope the government sent me unopened. I picked it up carefully with tongs and deposited it in the wood burning stove. I believe civil marriage is a crippled abomination, made in mockery of true marriage as orcs were made in mockery of elves, and it is not for me to voice an opinion one way or another as to what its definition should be. A pox on its loathsome spotty behind. Let it collapse under the weight of its own contradictions and be consigned to the dustbin of history in another few human lifetimes. Good riddance.
I did put up a few 'no' posters at work, since it irked me only seeing 'yes' ones about. It reminded me, just a little, of Istanbul immediately after the coup. I also posted a copy of the letter from the Bishop saying we should vote 'no' on a noticeboard. But, as he just exhorted us to do so, and didn't say it was a sin not to, I did not feel bound.
People ought to be able to bind themselves by whatever contracts they like, according to whatever new-fangled codes their imaginations can come up with, or with whatever time-honoured codes their ancestors have bound themselves with for generations. The role of government should be to see that people abide by the terms of their contracts. And that's all.