Caretaker Prime Minister Thaksin Shinawatra yesterday refused to say whether he would let his Thai Rak Thai Party MPs have a free vote when it came time to choose the next premier.

"I have my way [of doing things], which I will not discuss now. I will call a meeting later,'' he said.

Thaksin was giving interviews after having a medical check-up at Praram 9 Hospital. He said his doctor told him he is in good health in general, though some blood test results were pending, but he wanted to have a check-up because he had been coughing for some time.

Thaksin yesterday allayed fears that his party would break up if it could not settle on who would be the next prime minister. He said party members have the freedom to think and talk, but that ultimately they are disciplined.

He dismissed Democrat Party deputy leader Trairong Suwankhiri's comment that Thai Rak Thai Party deputy leader Pongthep Thepkanchana would be picked as the new premier.

"It's anyone's guess. I'll have to listen to the opinions of party members and think about it carefully,'' he said.

Thaksin said he would call a meeting of MPs-elect tomorrow  to discuss general topics. The identity of the next prime minister would not be on the agenda as it was too soon for such a discussion, he said.

He said he would spend Songkran either abroad or in Chiang Mai, and would return to Bangkok before April 23.

TRT factions have failed to agree about the candidate for the next prime minister. Some groups which support Somkid Jatusripitak are pushing for free vote while others want Thaksin or the party's executive board to have the final say about the matter.

Meanwhile, Thaksin will have lunch with Chat Thai Party leader Banharn Silapa-archa some time next week before he leaves for the United Kingdom, a source from the Thai Rak Thai Party said yesterday.

Thaksin called Banharn last Monday to discuss the political situation and during the conversation invited the Chat Thai leader for lunch, according to the source.

No exact date or time has been set but the source said it could be Wednesday, when both would have time in their busy schedules.

Thaksin is expected to leave for London on Thursday after casting his ballot in advance voting for the April 19 senatorial election.

Chat Thai, previously a coalition partner in a Thai Rak Thai-led government, joined other former opposition parties in boycotting the April 2 snap election.