Right to die campaigners are calling for a change in the law after it was revealed that one in five people who go to Switzerland for an assisted suicide are British.
Supporters say a big increase in so-called "suicide tourism" shows that terminally ill Britons should be able to end their lives at home.
ITV News Correspondent Harry Smith reports.
More top news
The polls have now closed, and the first result is expected in an hour.
Liverpool mounted another stirring comeback at Anfield, beating Villarreal 3-0 to reach the UEFA Europa League Final
The former BHS director has written to committee chairs, telling them to run their inquiries in a 'fair' and 'responsible' way.