Around 2,000 workers are expected to walk out of the DVLA offices in Swansea today in protest against planned office closures and disputes over pay.
It was announced in July that 450 jobs would be created at the company's headquarters in Swansea.
But the Public and Commercial Services Union says that the jobs announcement is diverting attention away from all the cuts they believe will be made to the DVLA over the next few years.
Workers in both the DVLA and Department for Transport, which have a shared service centre, are currently involved in an employment dispute with the DfT.
A PCS Union spokesperson said:
Today's strikes will be staggered, with DVLA workers in Morriston and Swansea Vale, Llansamlet stopping work for 3 hours at 2pm whilst their colleagues in the shared service centre, also at Swansea Vale, will strike for the full day.
The Department for Transport says contingency measures are in place to deal with the strikes.
A DfT spokesperson said:
A DVLA Spokesperson encouraged people to utilise online services during the strike: