It's over recent Census results, which showed a decline in the number of Welsh speakers.
The Welsh Government say the building remains open to staff and visitors as usual.
Cymdeithas are holding a peaceful protest at one of the entrances at the Welsh Government offices in Cardiff. The main reception remains open as usual to all staff and visitors.
More top news
New research shows more than two-thirds of people in Wales suffer from hay fever so badly it keeps them awake for more than an hour a night.
Figures show more than 2000 patients aged between 55 and 75 were admitted to Welsh hospitals with alcohol-related illness last year.
After a chilly start the sunshine will soon get to work, with temperatures on the up!