423. During an election period, a radio, television or cable broadcaster and the owner of a newspaper, periodical or other publication may make air time on the radio or television or space in the newspaper, periodical or other publication available free of charge to the leaders of the parties and to candidates, provided he offers such service equitably as to quality and quantity to all the candidates of the same electoral division or to all the leaders of the parties represented in the National Assembly or which obtained at least 3% of the valid votes at the last general election.