The Treaty on the Prohibition of Nuclear Weapons opened for signature on 20 September 2017, at the United Nations Headquarters in New York. This was a historic moment, when heads of states and foreign ministers gathered in New York to officially sign this groundbreaking treaty. More than 50 countries signed in the first 8 hours.

As the UK is against this international initiative, Scotland wanted to show solidarity and support for the ban treaty and organised its own Citizens Signing Ceremony in front of the Scottish Parliament. Many MSPs have signed the treaty along with campaigners, tourists from all parts of the word or local people passing by the parliament.