THE Provisional Airport Authority (PAA) is facing growing political pressure to settle its contract conditions row with construction firms. The Government's New Airport Projects Co-ordination Office (NAPCO), together with several prominent legislators, is becoming increasingly concerned the dispute may delay the airport indefinitely. The issue will come to a head on Friday when tenders are due to be returned for three further contracts covering site accommodation, water pipelines and passenger terminal foundations. But the Hong Kong Construction Association has instructed its members not to bid for the work. ''Having agreed to provide the PAA with the money for the advance works, there is mounting frustration within the Government that the authority is dragging its feet in pointless rows with its contractors,'' commented one informed source. Ronald Arculli, the Liberal Party legislator who represents the construction and real estate industries, agreed that if contractors boycotted Friday's deadline, the pressure on the PAA to reach a settlement would be enormous. ''There are three possible scenarios: some contractors tender; the boycott holds; or contractors accept the conditions and price the risks,'' he said. He believes this last possibility is the worst of all because of the effect it would have on Hong Kong's livelihood if construction of the airport was brought to an indefinite standstill as a result of contractors going bankrupt. Mr Arculli says this is a very real possibility if contractors accept the conditions as they are. The association made a last ditch plea for talks in a letter to the PAA last Friday. It said discussions to reach an agreement should take place as soon as possible so that if there were a deal contractors could still submit their tenders by Friday. But this offer has been snubbed by the PAA. Philip Bruce, the PAA's spokesman, confirmed that there were no meetings scheduled between the two sides before Friday. Legislators are also worried the dispute could be bogged down in a stalemate between the PAA and the association. Albert Chan Wai-yip, the United Democrats' infrastructure spokesman, said he had talked to the PAA and the Government because there are serious concerns that if the argument ''is not resolved quickly then there will be further delays''. ''I have had discussions with Works Branch and Economic Services and they are confident the row will be resolved soon,'' he said. Stephen Poon Kwok-lim, the Liberal Party's airport construction spokesman, also said he viewed the row with rising concern. ''I will be talking to Edward Ho Sing-tin, from the architects and surveyors constituency, to see if we should ask a couple of questions in the Legislative Council.''