The Parliament House is housed near the dusit zoo and chitralada palace and is along the way when you are going to the Wat Benchamabophit (Marble temple) so that if you are booked in a city temples tour, you can ask the driver for a quicl stop here for a photo shot. Current Prime Minister is Yingluck Shinawatra, the sister of much revered Thaksin Shinawatra, of the pheu thai party and the opposition is headed by the former prime minister Abhisit Vejajiva of the democrat party. It is located in the Dusit District of Bangkok
according to wikipedia:
The Parliament House of Thailand (Thai: อาคารรัฐสภาไทย) currently houses the National Assembly of Thailand, the legislative branch of the Royal Thai Government. The legislature is a bicameral body, consisting of two chambers: the upper house, (the Senate of Thailand), and the lower house, (the House of Representatives of Thailand). The Parliament House of Thailand is located in the Dusit district in the capital Bangkok, Thailand.
The National Assembly Hall was built during the reign of King Rama V. It was constructed out of marble in the Italian Renaissaance architectural style. This is also the old parliament building that is still used to hold important royal and state ceremonies. The large paved area in front of the building is where the annual Trooping of the Colours is held every December.
This huge official building is near the Dusit Zoo, behind the Vimanmek Teak Palace. It is used nowadays for royal and important state ceremonies. I didn't try to enter, but I think is not open to the public...