The Dalai Lama pleaded with exiled Tibetan MPs Monday to accept his resignation as their political leader, warning that a delayed handover could pose "an overwhelming challenge".

In a letter read out to the exiled parliament, the 75-year-old Nobel peace laureate argued that the Tibetan movement was now mature enough for a directly-elected political leader.

"If we have to remain in exile for several more decades, a time will inevitably come when I will no longer be able to provide leadership," he said in the letter read by the speaker.

"Therefore, it is necessary that we establish a sound system of governance while I remain able and healthy, in order that the exiled Tibetan administration can become self-reliant rather than being dependent on the Dalai Lama," he said.

The matter is scheduled to be debated on Tuesday, with the Dalai Lama requesting an amendment to the exiled government's constitution allowing him to step down.

The Dalai Lama's political title is largely symbolic and he will retain the more significant role of Tibet's spiritual leader.

Announcing his desire to step down last week, he made clear that he would not be withdrawing from public life and remained "committed to playing my part in the just cause of Tibet".

It is not the first time the Dalai Lama has asked to be released from his ceremonial political responsibilities, and the parliament has rejected similar requests in the past, arguing that there was no replacement of equal stature.

But leading political figures in the exile movement, including the Prime Minister Samdhong Rinpoche, suggested at a press conference later on Monday that lawmakers would accede to his wish this time.

"This decision of His Holiness the Dalai Lama is final. There is no going back," Rinpoche told reporters.

Dolma Gyari, deputy speaker of the government in exile, stressed that the move would affect all future Dalai Lamas, who are appointed according to the traditions of Tibetan Buddhism by senior monks.

"Having to take this decision is a grave matter for all of us," said Gyari.

There are three contenders for the post of prime minister, who will be elected in a vote this Sunday. Lobsang Sangay, currently a visiting research fellow at Harvard Law School, is seen as the front runner.

The other candidates are Tenzin Tethong, a former representative of the Dalai Lama in New York and Washington, and Tashi Wangdi, who has run half a dozen departments of the government-in-exile over the years.

In a debate hosted Sunday by US-based broadcaster Radio Free Asia, all three candidates voiced clear reservations about assuming the Dalai Lama's political title and urged him to reconsider stepping down.

"The Dalai Lama's decision to transfer authority to an elected Tibetan leadership naturally comes to me as a serious concern," said Lobsang Sangay.

"I support 100 percent that a collective appeal must be made to ask His Holiness to continue to hold leadership of the Tibetan people," he added.

Tethong said the Dalai Lama's leadership in all spheres was critical.

"I'm of the view that Tibetans must strongly urge him to continue to lead the Tibetan people as a whole," he said.

China, which brands the Dalai Lama a "splittist" bent on Tibetan independence, has accused him of playing political "tricks" to deceive the international community.

Analysts say relinquishing his political title would be largely symbolic, with the Dalai Lama remaining the global figurehead of the Tibetan movement and key arbiter on important policy.

"One thing is sure that even if there is a new political head, because of the standing and the reputation and the respect with which the Tibetans treat the Dalai Lama, he will continue to have a say in political matters," said H.H.S. Viswanathan from the Observer Research Foundation.

The Dalai Lama fled his homeland in 1959 after an unsuccessful uprising against Chinese rule, and established his exiled government in the northern Indian hill town of Dharamshala.