Thailand's reigning politician does not want to be elected

In Thailand, which is teetering on the brink of achieving full democracy, the most respected political institution is Kukrit Pramoj, who is hoping and praying he will not win the general election on April 18.

''If I became prime minister, I don't know how long I'd last,'' says Mr. Kukrit. ''Maybe just a number of days.'' He implied that he expected elements of the Army would force him out of office quickly.

''Then,'' he said, ''there might be bloodshed. I don't want people to kill each other.''

Against that explosive background the septuagenarian is running for election, having been elected prime minister during Thailand's brief experiment with democracy in the mid-1970s before the Army resumed control in 1976.

He leads the largest Thai political party, Social Action, and must be one of the few politicians left in the world who can easily draw 50,000 people to a rally as he did recently on the opening night of his campaign in Bangkok. He is a scathingly witty public speaker.

Speaking of the current prime minister, Gen. Prem Tinsulanond, who is perceived as a weak but steady leader, Kukrit said: ''Our prime minister is a delicate flower, which left alone would wither away. Therefore he has to be preserved between the pages of a book, probably a book of military history, until the Army opens the book to bring out the pressed pansy.''

He feels that General Prem as prime minister is not a free agent but has someone looking over his shoulder. ''I am here to declare war on people bringing in dictatorship,'' said Kukrit, who urges people to fight for their own freedom ''within the law.''

''How can I wage war, I don't even have a slingshot,'' he added. ''Our opponents are preparing to fight with tanks and guns.'' They were, he explained, not all those in the military, but ''a few Army officers and their civilian allies.''

At their head is the controversial Army commander inchief, Gen. Arthit Kamlang-ek, who has been leading a campaign to retain the Army's central role in running Thailand. Kukrit opposed him and got the better of the encounter when Parliament in March rejected Army proposals designed to consolidate its grip on political power.

But Prime Minister Prem surprised most everyone by decreeing an election to be held on April 18, just three days before election rules are due to change. The new rules will make it easier for one party, such as Social Action, to gain a majority. Under the old rules, however, the election may result in no clear winner, with the military being asked to help form a new government.

''We fought by the rules and we won,'' says Kukrit, ''but when we came out of the ring, the other side hit us with chairs.''

On the eve of Parliament's final vote, Kukrit published in his newspaper, Siam Rath, what he claimed was a secret document setting out the Army's political plan for the country. He said it had been drawn up according to communist ideology by a communist defector, Prasert Sapsunthorn, former Central Committee member of the Communist Party of Thailand and an adviser to the internal security operations command.

One section of the plan appeared to undermine the stature of the King, who is still highly revered here. This sensational disclosure by Kukrit probably persuaded some parliamentarians to change sides and vote against the Army proposals.

Kukrit has been in the front line of the fight for free speech, government by reason, and constitutionalism since he entered Parliament in 1946. This has brought him into conflict with most of Thailand's military governments.

He was arrested several times and was once sentenced to jail for libeling the American ambassador whose remarks, according to Kukrit, had condoned the Thai government's dubious electoral methods in 1957. The government was overthrown before Kukrit began his prison term and soon afterwards the appeals court quashed the conviction.

His newspaper fought government censorship over a long period, at one time refusing to publish political news altogether. Instead it ran, as an example, mockingly serious articles about the number of betel nuts on trees outside Kukrit's office. On another occasion he sent reporters to count the number of doors and windows in the Ministry of Defense.

The government did not know what to make of his campaign but ultimately offered to lift censorship if the paper dropped its bizarre stories.

''End censorship first,'' Kukrit replied. The government complied.

Kukrit says of the military leaders: ''We cannot beat them with guns so we must make fun of them. Encourage people to laugh at them. Laugh them down. Kick them with our laughter.''

It is an unusual strategy in Asia, but with such methods Kukrit has made the Thai people much more politically conscious than they were at the time of the last violent military coup 61/2 years ago.

In 1948, he resigned as deputy finance minister when Parliament voted itself a substantial salary increase immediately after an election. Next day crowds gathered outside his house to do him honor by symbolically placing gold leaf on him, according to a Thai Buddhist custom.

Kukrit is a historian, novelist, and authority on Thai culture. Twenty years ago he made a notable appearance in a Hollywood movie, ''The Ugly American,'' which starred Marlon Brando. The film for a time was banned by the Thai government. In it, Kukrit played prime minister of a mythical country named Sarkhan.

His conflicts with Americans in the film were repeated later in real life when, as prime minister of Thailand at the end of the Vietnam war, he ordered American forces to vacate air bases in the northeast. Declaring that Thailand was ''not in the domino club,'' he said it was no longer appropriate for foreign forces to be on Thai territory.

About the same time he established relations with communist China, a relationship now of profound importance to Thailand in its confrontation with Vietnam over Kampuchea. Nevertheless Kukrit, who was educated in England and has a degree from Oxford, believes his country should adhere to the Western world because of its ideals of liberalism and democracy.

His most famous domestic achievement, an imaginative rural development program, might have been the brainchild of a Western social democrat. This project channeled central government funds directly to small rural communities to finance development projects of their own choice. It had never been done before in Thailand and was immediately condemned by the military, although it was later adopted.

In the current campaign, Kukrit's election slogan is: ''We've done it and we can do it again.'' In fact, he does not expect to win enough seats to form a government but is willing to participate in a coalition with the Democratic Party, the center-right parent party of Kukrit's Social Action Party.

His chief opponent on the hustings is an old foe, Samak Sundaravej, leader of the Thai People's Party (Prachakon Thai), the strongest in Bangkok. Mr. Samak, who has close links with the Army, held the key post of interior minister in the last period of repressive military rule in 1976-77.