Civil servants have overruled the Oxford English Dictionary and hundreds years of common usage effectively abolishing the traditional meaning of the words for spouses.
The landmark change is contained in the fine print of new official legal guidance drawn up for MPs and peers as the Government’s same-sex marriage bill is debated.
It comes as part of a Government initiative to “clarify” what words will mean when gay marriage becomes law.
But critics described it as the vocabulary of “cloud cuckoo land”.
It follows claims by opponents of the redefinition of marriage that universally understood terms such as father and mother might be simply deleted by bureaucrats on official forms.