His retirement from Parliament coincided with his appointment as chief executive of the Royal Forest and Bird Protection Society of New Zealand, a role he held until 2022.

[3] Hague met his partner, Ian, in 1984 while protesting an upcoming New Zealand rugby union tour of South Africa, which was later cancelled.

He edited Terry Stewart's 1996 book Invisible families: a New Zealand resource for parents of lesbian and gay children.

[7] As director, Hague criticised the 1999 government decision, promoted by immigration minister Tuariki Delamere, to ban HIV-positive migrants from entering New Zealand, saying it would be un-humanitarian.

[13] Hague was selected as the Green Party candidate for the West Coast-Tasman electorate ahead of the 2008 general election.

"[16] Hague's candidacy followed several years of political activity with the Greens and unsuccessful attempts from both Labour and National to recruit him to stand for their parties.

[19] He successfully campaigned against Meridian Energy's plans to dam the Mōkihinui River between 2009 and 2012, and advocated for reform of the Accident Compensation Corporation in 2012.

[23] Hague said once the bill had passed its third reading, in April 2013, there would be a number of "incredibly emotional" weddings between gay couples.

[30][31] Hague holds several health sector appointments made by the Sixth Labour Government, which came to power the year after he left Parliament.

In 2019, he was appointed a member of the interim board of Te Hiringa Mahara, the Mental Health and Wellbeing Commission and later became its deputy chair.