A petition against an eight-story Union Jack that is set to be emblazoned on the corner of the new UK government building near Sgwâr Canolog in the centre of Caerdydd has amassed more than ten thousand signatures.
The pro-independence campaign group YesCymru launched the petition on Thursday.
The petition is calling on Caerdydd Councillor Keith Jones, chair of the capital's planning committee, to reverse the decision which has been given the go-ahead because of its classification as an "advertisement."
While granting permission, Caerdydd Council acknowledged the "large scale" of the vinyl graphic, but nevertheless approved the proposal on the grounds that it is "appropriately proportioned in relation to the overall scale of the building."
YesCymru called the decision to add a Union Jack to the building "an act of political symbolism designed to promote 'muscular unionism' a reminder to the people of Wales of their subservient status in the United Kingdom."
The petition states: "We believe that as the capital city of Wales, visitors, commuters and residents should not be faced with a gigantic Union Jack flag on arrival at Cardiff Central railway station [...]
"This flag does not represent the people of Wales and is a blatant political act designed to act as a provocation to the people of Wales."