Services have been disrupted as up to 23,000 civil servants in Wales staged a strike as part of a UK-wide protest over jobs, pay and privatisation.
Swansea Magistrates court administration staff man a picket
Job centres, benefit offices, driving exams, coastguards and customs work were hit by the Public and Commercial Services Union (PCS) action.
The strike follows Chancellor Gordon Brown's 2004 announcement that 104,000 civil servant posts would be cut.
The union said Wales stood to lose more than 10,000 of those jobs by 2011.
The PCS said the cuts programme would have a bigger impact on the Welsh economy than any other part of the UK because Wales has proportionately more civil servants.
Picket lines were set up outside official buildings across the country and the union said it was also drawing up plans for further "guerrilla" action at later dates.
Margaret Davies, who has worked at the Merthyr Tydfil tax office for 10 years, said civil servants in Wales were "disappointed" with they way they were being treated.
Some civil servants says they feel disillusioned about their future
"We're undergoing a consultation where [the UK Government] intend moving work out of Merthyr tax office and centralising it in Cardiff," she said.
"We in Merthyr are worried about our jobs. We're worried whether our jobs will even exist in a year's time and we feel we need to strike to get the point over to central government that we will not be treated this way."
Chris Hall, who serves on the union's national executive, and is a court clerk based in Wrexham said: "Hard-working staff and members across north Wales are disillusioned and fear for their futures, with pensions under threat and jobs already being outsourced to private companies.
"Things will simply get worse if we take no action, so reluctantly we have been compelled to make our concerns public."
Speakers from a number of political parties addressed a rally at the Temple of Peace in Cardiff.
Marches or meetings were also held at Bangor, Aberystwyth, Carmarthen, Newport, Swansea and Wrexham.
Debates at the Welsh assembly were cancelled and the Senedd debating chamber was closed to the public.
Assembly Presiding Officer Lord Elis Thomas said: "As a democratic institution, the assembly respects the right of its staff to take legal strike action."
Steve Lazenby, organiser of the PCS in south west Wales, said the strike was a "massive success".
He added: "This action was not taken lightly, and we apologise to members of the public for any inconvenience that was caused to them.
"[But] if people support the concept of local services accountable to local people, then action is required now."