Thailand's army-stacked parliament will vote in an impeachment hearing of ousted prime minister Yingluck Shinawatra on Friday, testing a fragile calm between the rural poor and the royalist establishment backed by the Bangkok middle class.

A guilty verdict on the charge of dereliction of duty could see Yingluck - who was removed from office for abuse of power in May, days before a military coup - banned from politics for five years.

Security near parliament was tight on Thursday, with about 100 soldiers and police officers stationed around the building. There were no visible protests.