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.
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All very dull and grey over the next few days unfortunately, but at least temperatures are degrees milder!
Conservatives claim the poor PISA ranking is a 'scandal of monumental proportions.' Plaid Cymru say the Welsh government has 'failed again.'
Unions are calling on the Welsh Government not to panic and to provide support for teaching staff following the PISA rankings publication.