Thailand's ruling People Power Party has suffered a string of setbacks in court this week.

On Tuesday, Thailand's Supreme Court found former parliamentary speaker Yongyuth Tiyapairat guilty of vote fraud in last year's legislative elections.

The court has barred him from politics for five years. Yongyuth stepped down from his post earlier this year to contest the vote buying charges.

Wednesday, Thailand's Constitutional Court, which oversees the appointment of officials and government policies, ordered the removal the country's health minister, Chiya Sasomsub. He is accused of violating regulations that require officials to reveal their assets.

The rulings come as opposition lawmakers are preparing to launch an impeachment motion against the foreign minister.

The People Power Party is closely linked to former Prime Minister Thaksin Shinawatra, who was ousted from office nearly two years ago in a bloodless military coup.

The party has been heading Thailand's coalition government since winning parliamentary elections last year. Criticism of the party's links to Mr. Thaksin have triggered massive demonstrations in recent weeks.

Late last month, the opposition tried to pass a vote of no-confidence against Thailand's prime minister. The motion failed.  

Some information for this report was provided by AFP, AP and Reuters.