The new forms - which give the option of listing "parent one"
and "parent two" alongside "mother" and "father" - are due to be
implemented by the start of 2012.
It comes after the USA made similar modifications earlier this
year.
The proposals also include sex-free passports to allow transgender
people to opt out of identifying themselves as either male or
female, report the BBC.
The change has been welcomed by LGBT groups, who complained that
the previous format was too hetero-normative and ignored people in
transition or who are transgender.
According to the Home Office, the move will ensure that passports
are issued "securely and safely to the right person."
An Identity and Passport Service (IPS) spokeswoman said: "It is
essential that any parent provides the necessary information on
their status as parents or guardians when applying for a passport
on behalf of their child.
"This protects the interests of the child and ensures that IPS are
able to issue passports securely and safely to the right
person.
"The passport application form is therefore being updated to
incorporate same-sex parents."