OPPOSITION lawmakers failed to gain enough votes yesterday in their attempt to freeze the budget for Taiwan's planned fourth nuclear power plant. The vote will allow the island's state-run power company, to accept bids for the US$6.45 billion (about HK$50.01 billion) plant. The Legislative Yuan voted 76 to 57 with four abstentions to reaffirm a vote taken in a chaotic meeting on June 23 against a motion by Democratic Progressive Party (DPP) lawmakers to freeze NT$7.5 billion (HK$2.18 billion) in funds for the project. Yesterday's vote ends the second annual campaign against the plant by a coalition of environmental activists and the DPP. Opponents maintain nuclear power is unsafe and unnecessary in Taiwan. The ballot was mostly along party lines. Spurred on by a message in favour of the plant from President Lee Teng-hui, who is also Kuomintang chairman, most ruling party legislators voted for it. In opposition were 49 DPP members, five KMT members and three independents. But yesterday's vote may not yet be definitive. Votes in favour fell short of a majority in the 161-member assembly. Also, a number of KMT members choose not to cast ballots. Said independent legislator Chen Je-nan, who voted against the plant: ''If the existing three plants operate safely in the coming years, the fourth plant is likely to be built. But if problems persist, today's result could well be reversed.'' Taiwan Power Co officials said invitations to bid for the nuclear plant had already been issued. Taiwan's power monopoly expects to receive all the bids by September and make a decision by the end of March 1994. Four firms, Westinghouse, General Electric, Framatome and ABB (Combustion Engineering), are expected to submit bids for the plant, which is to be built at Kungliao in northeast Taiwan. More than 10 companies may bid for power generation components. As in past votes, several hundred demonstrators, many from Kungliao, protested in front of the Legislative Yuan. No major clashes took place between demonstrators and police, but opposition lawmakers protested strongly against the decision by administrators to ban public observers from the proceedings.