More than 100 security guards were deployed at the party headquarters, where ceremonies to mark the occasion took place.

Thaksin came to the party headquarter with his wife, Khunying Pojaman, and their children.

When he entered the compound, Thaksin teased PM's Office Minister Suranand Vejjajiva, who has been rumoured to be considering leaving the Cabinet.

The PM was heard saying: "Ah, you are still here. I hear that you are making up your mind [whether to resign or not]."

Suranand smiled and responded: "Reporters just asked me if I brought my resignation letter with me."

Suranand lined up with other senior party members to receive Thaksin and his family members at the entrance.

On Thursday evening, Suranand gave an interview upon arrival at Bangkok Airport from a US trip. Some observers felt his words reflected his unhappiness with the government's performance.

Suranand yesterday dismissed press reports that he was feeling slighted and was considering leaving the caretaker government. However, he declined to confirm or deny that his family urged him to resign his seat.

In a related development, Democrat Party spokesman Ong-art Klampaiboon said he believed that many Cabinet members were getting uncomfortable, as the caretaker PM had been engaged in a dispute with several people in society, regardless of their stature.

At noon, a group of students from Ramkhamhaeng University came to the ruling party's head office, taking with them a caricature cartoon featuring Thaksin embracing US President George W Bush and a locket bearing a likeness of the American leader. They said they were going to present the locket to Thaksin as a lucky charm.

But the students were blocked at the entrance by policemen who told them to "go back".

The students also read a statement at the gate, saying: "We are here to celebrate the eighth anniversary of Thai Rak Thai. We bring a picture of the US president and his locket. We hope the PM wears it for his safety."

While the statement was being read, some party members scolded the students and told them to take the items away. But the students instead left them at the party's nameplate.

After a religious ceremony, Thaksin received flower baskets from party supporters and well-wishers.

Thaksin led party members in donating blood as part of a party campaign to make a tribute to His Majesty the King.

He was heard telling a nurse who was about to draw his blood that "it may be hard to find my veins because I have got too much fat". Thaksin was looking away as the nurse was drawing blood from his forearm.

Meanwhile, National Intelligence Agency director Jumpol Manmai led a team of senior police officers to visit Thaksin at Thai Rak Thai headquarters. Jumpol is the leader of graduates of Police Cadet Class 26, of which Thaksin is part.