By Lois Jones THE British parents of a 17-year old, killed last year on the Ibiza-Sant Antoni highway, yesterday welcomed Prime Minister Tony Blair's appeal to Spanish authorities to improve safety conditions on this infamous stretch of road. Tony Blair has asked his Minister of Foreign Affairs, Jack Straw, to liaise with Spanish authorities and set up a working party to look at why so many pedestrians have been killed on the highway over the past few years. Two years ago Boy George launched a campaign for road improvements after the death of a teenage Welsh girl. Mr Straw will ask the appropriate legal office, in this case the Council of Ibiza and Formentera, to reduce the current speed limit, arrange for improved lighting and the repainting of faded road markings, to schedule the construction of clear pavement walkways and safe pedestrian crossings. The continual dangers along this route were brought to the attention of the British Prime Minister by the Member of Parliament Mark Tami, who at the request of the parents of David Holloway, who died last summer after being run down on this same stretch of road, decided to take up the case. Tami recently said he wants to take the late Holloway's cause to the European Tribunal. Yesterday, Tami explained that Tony Blair, following 32 British deaths there in the past few years, wished to be kept informed as to what action should be taken to improve the state of this road.