Charnvit Kasetsiri, a former Thammasat University rector and prominent historian, suggested that the anti-Thaksin People's Alliance for Democracy (PAD) cancel its campaign to have him expelled from the Kingdom.

He said they should let Thaksin return so he could be tried for his past wrongdoing.

Thaksin is on a two-week trip to Europe and America and is scheduled to return on Friday.

The PAD has planned a mass rally on Wednesday to demand that Thaksin quit politics and go into exile.

PAD spokesman Suriyasai Katasila has said that various organisations, including the Office of the Auditor-General, were able to start investigating the sale of Shin Corp shares by Thaksin's family after he left the country on September 9. His return might disrupt the investigations, he said.

PAD leader Sondhi Limthongkul also said Thaksin should not return to Thailand. "He should stay abroad because, while he's away, things are rather peaceful here," Sondhi said.

"I think the PAD should not rally to demand Thaksin's exile," Charnvit said.

"Why don't they let him return to face the problems he has created for the country ... instead of letting him spend money in London and shop at Harrods every day."

He said the 1976 student protests against the return to Thailand by Thanom Kittikachorn, his son, Colonel Narong and Field Marshal Prapas Charusathian allowed them to live happily abroad instead of being brought to justice in the Kingdom.

"For example, Narong opened a Thai restaurant in Germany and lived there happily," Charnvit said.

The Thai Rak Thai Party sees the rally as illegal and will file a complaint with the Election Commission seeking to have it stopped.

A party legal adviser Kuthep Saikrajang said yesterday an approach to the EC would be made today.

Kuthep said the party viewed the rally as a violation of Article 44 of the Members of Parliament and Senators Election Act. The rally could produce an advantage to some candidates or a disadvantage to others.

He said the EC would be asked to clearly define what activities were permitted and what were not.

Suriyasai said the PAD chose to rally on Wednesday because September 20 is national state enterprise day to commemorate the establishment of Thailand's first state enterprise by King Rama V. About 50,000 employees of 42 state enterprises were expected to join the rally.

He said it would not violate the election law as the people have their constitutional right to demonstrate.

But caretaker Prime Minister's Office Minister Suranand Vejjajiva and Thai Rak Thai spokesman Sita Divari called on the government's opponents to be patient and respect democracy.

Suranand said the government had no problem with "democratic rallies" and the PAD should ensure their gatherings did not flout the principles of democracy.

He warned the Thaksin-support faction called Udon People's Club to avoid clashes with anti-government groups.