Sir Elton has vowed to wed David Furnish again if gay marriage is legalised.
The entertainer, who has a 20-month-old son with the Canadian producer, has written a piece for The Independent, campaigning for gay marriage.
Elton recalled his civil partnership with David in 2005 on the first day it was legalised in Britain, and said: "Now, six and half years on from the happiest day of my life, when we have a beautiful boy called Zachary, I would love nothing more than to make history again by marrying David.
"If we legalise gay marriage in Britain, you can bet your last penny that I'll be pushing to call him my husband at the first opportunity."
Elton insisted calling David his "partner" does not do their 20-year relationship justice.
He said: "There is a world of difference between calling someone your 'partner' and calling them your 'husband'. 'Partner' is a word that should be preserved for people you play tennis with, or work alongside in business.
"It doesn't come close to describing the love that I have for David, and he for me. In contrast, 'husband' does. A 'husband' is somebody that you cherish forever, that you would give up everything for, that you love in sickness and in health.
"Until the law recognises David Furnish is my husband, and not merely my partner, the law won't describe the man I know and adore."
He added: "We should show that we are a country committed to the sacred institution of marriage, proud of out tolerant heritage, and brave enough to let lovers like David and I call each other a husband."