Crispin was elected MP for Reigate in 1997 having formerly served as an army officer.
In Parliament, Crispin has served in the Shadow Cabinet with briefs including trade and energy and security and counter-terrorism. He has served as both Minister for Prisons and as Chairman of the Foreign Affairs Committee.
Crispin is currently the Chair of the All-Party Parliamentary Group (APPG) on Global LGBT Rights, co-chair of the APPG for Humanism and co-Chair of the APPG on Drug Policy Reform. He is the Conservative Middle East Council’s Vice-Chair.
In January 2019 Crispin set up and launched the Conservative Drug Policy Reform Group whose objective is to promote evidence-based drug policy reform on the centre right. He is currently the Group’s unremunerated Chair and Chief Executive Officer.