The Office for National Statistics (ONS) will be turning landmarks purple as part of the integrated campaign to promote this year's census.
For the activity, called "Purple light-up", M&C Saatchi has co-ordinated hundreds of buildings and landmarks in England and Wales to display the census 2021 brand colour that was featured in its TV spot.
Lights will glow purple for three days from 19 March at sites including Wales Millennium Centre in Cardiff, Blackpool Tower, London's BT Tower and Brixton Town Hall.
Scarlett Such, account director, M&C Saatchi, said: “We wanted to create a crescendo ahead of census weekend to serve as a prominent visual reminder for people to take part if they haven’t already.
“The buildings that have been illuminated are landmarks of the communities they are located in and we sought to capture that parallel to highlight the important role the census plays in shaping and building communities throughout England and Wales.”
Everyone in England and Wales is legally required to fill out details about themselves and their household on Sunday (21 March) and could be fined £1,000 if they do not do so. The census happens every 10 years and is used by the government and local authorities in their planning of public sector services.
The M&C Saatchi team included Ros Trinick, communications and PR director; Leon Emirali, business director; Zoe Kusnierz, account manager; Jess Scully, account manager; and producer Imogen McManus.
Pete Benton, director of census operations, ONS, said: "The census is such an important undertaking that helps inform the vital services we all rely on every single day within our communities.
"We wanted to shine a (purple!) light on the buildings and landmarks that matter most to their local areas, highlighting the importance of the census in helping shape the communities we live in."
The ONS is aiming to achieve more than 75% online completion of the census and M&C Saatchi’s activity is part of those efforts.
M&C Saatchi also created the campaign film "It's about us", which featured people from all walks of life engaging in daily activities and posing in front of a purple backdrop.