Nigel Dodds of the Democratic Unionist Party, who called for legal discrimination against LGBT+ people, has lost his seat.
The DUP’s Westminster leader lost the Belfast North seat he has held since 2001 in Thursday’s election.
Dodds received 21,135 votes, behind Sinn Féin’s John Finucane on 23,078.
Nigel Dodds opposed equal marriage, inclusive education, cakes for gay people
In March, Dodds was one of just 21 MPs to vote against guidelines on LGBT-inclusive sex and relationship education.
He also opposed the extension of equal marriage to Northern Ireland, claiming the decision to secure equality in the absence of the Northern Ireland assembly was “driving a coach and horses through the principle of devolution, overriding the concerns of people in Northern Ireland.”
Dodds has previously called for a “conscience clause” to permit anti-LGBT discrimination on the grounds of religion.
After a Christian bakery was found to have discriminated by refusing to bake a ‘gay’ cake, Mr Dodds called for equality law to be re-written to protect Christians.
He said: “The case reopens the debate about how exactly religious belief is respected within the United Kingdom and the need for someone’s conscience to be protected whilst ensuring that discrimination does not occur.”
He is not the only party leader to lose his seat on Thursday, with the pro-LGBT Lib Dem leader Jo Swinson also ejected from Parliament.
DUP wants protections for people who oppose gay weddings
In October, DUP leader Arlene Foster reaffirmed the party’s opposition to same-sex weddings.
With the legislation to extend equal marriage now in effect, Foster confirmed that the party still opposes the “redefinition of marriage” and will seek to have religious protections against same-sex marriage written into law.