Janeen (formerly John, a Grimsby trawlerman) Newman, 47, and David (age and previous name undisclosed) Willis, who has an eight- year-old daughter, already live together in Louth, in Lincolnshire.
They met five years ago as John was preparing for the operation which made him Janeen, and yesterday they gave the text of their royal letter to the Grimsby Evening Telegraph, which splashed it on the front page. Last night, bidding in a Fleet Street auction for their story was understood to have gone well into five figures.
Under British law, it is possible to marry only as the gender on your birth certificate. You can change your name and the title by which the world addresses you, but you cannot have a chromosome recount.
In the letter to Buckingham Palace Miss Newman says: 'My partner David Willis and I wish to be married. We intend to spend the rest of our lives together and want to solemnise our relationship legally and provide a formal family unit in which to raise David's daughter.
'We are very ordinary citizens and seek only to be able to live our lives as other citizens are allowed to do.
'We wish to live industrious and integrated lives in society.'
Compelling though their arguments may be, the pair are unlikely to convince Her Majesty that she should persuade her Government to change the law.
Probably the most useful advice from Her Majesty's staff, well used as they are to desperate pleas from subjects when all else has failed, would be that if the pair are really determined, the law cannot stop them marrying.
Mr Willis can even wear top hat and tails, Miss Newman can wear a long white gown and veil. The only snag is that he must promise to take her as his 'lawful wedded husband', while she, in return, must take him as her 'wife'.