TAIPEI, Jan 28 (AFP) - A group of environmental activists plans to launch a 30-hour sit-in outside the Taiwan parliament Monday ahead of an extraordinary session over a controversial nuclear power project, organisers said Sunday.

The group, comprising university professors, power experts and female activists, wants to back the Democratic Progressive Party (DPP) government's decision to scrap a new nuclear power plant.

"We hope to make the parliament aware that anti-nuclear is a prevailing voice of the Taiwanese," Chen Hui-hsin, professor of National Chengchi University, told AFP.

However, 50 percent of the 787 people interviewed on the issue by the United Daily News earlier this month were in favor of the project while just 33 percent were against.

The row erupted after Premier Chang Chun-hsiung said on October 27 that the government was scrapping the nuclear plant project on safety and environmental grounds in defiance of a decision by parliament in 1996.

On January 15, Taiwan's highest legal body, the 15 Grand Justices, ruled there were "flaws" in the decision-making process as Chang had failed to seek prior approval from parliament in accordance with the island's constitution.

The grand justices said the premier had to submit the case for discussions and seek endorsement by parliament.

But they stopped short of saying the cabinet move had violated the constitution.

It was reported that the parliament, controlled by opposition parties, would only allow the premier to deliver a 10-minute speech and would then push for a vote to end the uncertainty shrouding the 5.6 billion US dollar project.

"The public confidence will stay low if the project is not revived," said Hung Yu-chin, a senior parliamentarian with the leading opposition Kuomintang (KMT).

Share prices have shed some 40 percent since the pro-independence DPP overturned 50 years of Kuomintang rule on the island when it won the presidential elections in March last year.

Now in recess, the parliament has decided to hold an extraordinary session on Tuesday and Wednesday. The new session is slated for February 20.

The KMT now holds 115 seats in the 221-seat parliament while the DPP has only 68 seats.

The ruling party has shown no sign of concessions and pledged to support the premier in line with its party platform of building a no-nuclear homeland in Taiwan.

The state-run Taiwan Power Company (Taipower) currently operates three nuclear power plants on the island.

Its plan to build the fourth nuclear power plant was pushed through in October 1996 by the then-ruling KMT government despite years of violent protests by environmentalists and local residents.

Taipower has spent 52.7 billion Taiwan dollars (1.6 billion US) on the initial construction of the Kungliao plant, which began in March 1999, and other related costs since work was halted in late 2000, according to the latest company figures.