Dili – East Timor's fledgling lawmaking body on Tuesday adopted the tongues of both their native ancestors and Portuguese colonisers as the official languages of the world's newest nation.

Tetum and Portuguese were given the nod by 80 members of the 88-person constituent assembly, a body elected three months ago to draft a founding constitution for the half-island territory now five months away from full independence. Three members abstained from Tuesday's constitutional debate, while another five were absent.

"We have to think of our future as a developing country. If we don't use Portuguese we will be isolated," assembly member Joao Carrascalao, of the UDT party, told journalists after voting in favour of both languages.

Mariano Sabino Lopes, of the youth-oriented Democratic Party, said Tetum had to be included because it was the language of the 24-year resistance fight against Indonesia. "We used Tetum to recruit and unite people in the struggle against Indonesia," Lopes, once an active resistance supporter, said. "[Independence leader] Xanana Gusmao used Tetum when he wrote letters to the youth, so we've always considered it the language of resistance."

Lopes said the adoption of both Tetum and Portuguese would eliminate a feared division between the older Portuguese-fluent generation and the younger Tetum-fluent youth, who are also proficient in English and/or Indonesian. "It means both old and young will have access to jobs," he added.

East Timorese voted overwhelmingly for independence in a United Nations-backed plebiscite in 1999, ending 24 years of brutual military-backed rule by Indonesia that followed Portugal's 400-year colonial regime.

A hybrid version of Tetum, an Austronesian language that was infused with Portuguese in colonial times, spread among the population until an estimated 60 percent used it. Portuguese was banned by Indonesian rulers in 1981, six years after Jakarta's annexation of East Timor, but they failed to wipe it out. An estimated 10 percent of the population are fluent in it.

A proposal to include the most commonly spoken tongue, Bahasa Indonesia, in the official languages was overruled. "Around 75 percent of our people can speak Bahasa because we had to learn it during Indonesian time, that's why we wanted it adopted," said Antonius Ximenes, whose Christian Democratic Party put forward the proposal. "Also because we are considered part of Asia, and Bahasa is an Asian language."

The assembly has been debating a draft constitution, which was completed on November 27, since December 3. The United Nations, which has been administering East Timor since late 1999, will hand over full independence on May 20 next year.