Union members went on strike at Parliament for two hours on Thursday in a protest over their pay.
The action involved 170 Public Service Association members including security and reception staff.
The PSA says it has been trying to negotiate a new collective employment contract with the Parliamentary Service since February.
It says Thursday afternoon's strike, for which only half an hour's notice was given, was an escalation of action by workers who are upset at their pay rate being frozen.
The action coincided with Parliament's Question Time, but did not upset proceedings.
Two stopwork meetings lasting two hours were held earlier in the month and a rally lasting an hour was held outside Parliament two weeks ago.
PSA members at the Ministry of Justice held a one-hour strike earlier on Thursday, as part of a pay dispute.
It was the second one-hour stoppage this week. Another was held on Tuesday.
