India is expected to elect one of Prime Minister Indira Gandhi's most faithful supporters as president Monday amid opposition charges that Gandhi has politicized the independent character of the job of head of state.

Former home minister Zail Singh is the overwhelming favorite to win the presidency in an indirect election by members of India's state assemblies and national parliament, which are dominated by Gandhi's Congress-I Party.

He is being opposed by a former supreme court judge, H. R. Khanna, who entered the race after opposition leaders failed to persuade Gandhi to pick a consensus candidate.

While India's president is largely a ceremonial figure, he is the commander in chief of the military forces and the glue that holds the country together during times of political instability. The president, for instance, chooses the person to form a new government after a parliamentary no-confidence vote, and thus is in a position to influence the future course of the country.

Traditionally, the president has been a man of stature who has remained above party politics.

Although Singh is a strong Gandhi partisan, he has promised to be nonpartisan if elected. "I will not permit the opposition or the Congress-I to establish an office in the Rashtrapathi Bhavan," Singh said, referring to the imposing red sandstone president's house originally built for the British viceroy.

Singh, 66, is considered by many to be an inept political figure because he continually puts his foot in his mouth. This spring, for instance, he praised Adolf Hitler in a parliamentary speech that embarrassed other Gandhi aides so much that they had his remarks expunged.

He appears to have been picked for president by Gandhi because of his loyalty to her, her party and her family.

"If my leader had said I should pick up a broom and be a sweeper, I would have done that," he said in a statement that revealed his devotion to Gandhi, since being a sweeper is considered demeaning in India.

The Indian Express, a leading opposition newspaper, compared him in an editorial to "Caligula's horse," and said his main qualification for being India's seventh president is "his total and complete loyalty to the prime minister."

His nomination, however, won great support from among India's small but prominent Sikh religious minority. If he wins as expected, Singh will be the first Sikh to be president.

His victory may quiet complaints of discrimination by India's 13 million Sikhs. Gandhi is known to be concerned about a minuscule but vocal separatist movement to form a Sikh nation of Khalistan.

Singh would succeed N. Sanjiva Reddy, who in the last months of a five-year term that expires July 25 has antagonized Gandhi by his outspoken criticism of growing corruption in Indian life.