Last July during the height of Uganda's fuel crisis, President Idi Amin made preparations to abdicate and take up asylum in Libya, a high-ranking Ugandan army officer who fled to Kenya earlier this month said today.

The officer, who refused to be identified, revealed that by the time Kenya resumed Uganda's fuel suplies after a six-week halt, Amin had already flown his two present wives and many of his children to Libya.

"If the crisis had continued another week to two there would have been a change in Uganda," said the officer, who has served with Amin since 1960 and who has held prominent government posts since Amin seized power in 1971.

At the time, the critical shortage of fuel stopped all civilian and military traffic. Fuel supplies were resumed after pressure from William Eteki, the secretary general of the Organization of African Unity. Eteki was also instrumental in ending the hostilities that brought the two countries to the brink or war.

The fuel supplies had been cut off by Kenya amid growing hostility between the two countries, which reached a high point after the Israeli raid on Entebee airport that freed more than 100 hostages from pro-Arab hijackers.

Kenya claimed that it cut Uganda's fuel supplies because Uganda was not paying its bills. Uganda was so short of fuel by the end of the blockade that it would have been unable to fight.Solders were calling for Amin's resignation.

The refugee officer called Amin, "the second Hitler." He has joined many other Ugandan exiles in calling for international sanctions to bring down Amin's dictatorship.

He is pessimistic that Ugandans themselves will be able to get rid of Amin. "Exiles," he said, "have no money. We all have people inside the country and, if any of us are suspected, Amin will kill all of our relatives there."

"Only international aggression or economic pressure," will bring Amin down," he said. The officer called on all countries to sever trade and diplomatic links with Uganda.

Meanwhile, the Nairobi Standard newspaper reported today that a clandestine resistance group inside Uganda, the Uganda People's Passive Resistance Front, intends to Poison Ugandan coffee and tea in an attempt to cut off the money for Amin's militry supplies.

The group was quoted as saying, "We shall naturally be saddened by any loss of live resulting from contact with contaminated Ugandan goods, but you must hold Amin and yourself responsible."

No spokesman for the resistance [WORD ILLEGIBLE] could be found in Nairobi. Observers believe that the group is more[WORD ILLEGIBLE] to be the invention of exiles in Kenya than an authentic internal resistance movement. It is also thought that the likehood of crop poisoning is small.

(Amin accused the U.S. Central Intelligence Agency today of using Christian denominations as a cover for subversion and said he would prohibit all foreign aid to churches in his country, according to Uganda radio, which was monitored in Nairobi by news agencies.)