BRATISLAVA (Reuters) - More than 100 Slovak journalists gathered outside parliament on Tuesday to protest against a planned tax increase they said would threaten the existence of many newspapers. Parliament this week debates a proposal by the government of Prime Minister Vladimír Mečiar to increase value added tax (VAT) to 23 percent from the existing six percent on newspapers with more than 10 percent advertising content. Such VAT rises have already been criticised by the European Parliament. Jan Fuele, chairman of the Syndicate of Slovak Journalists, handed deputies arriving for Tuesday`s parliament session a memorandum showing the effect a VAT rise would have on the country`s independent media. According to the syndicate`s analysis, the increase in VAT would increase the price of dailies from seven to 10 crowns a copy resulting in an average 20 percent drop in circulation. The proposal has also sparked criticism by foreign journalist organisations. Politicians of Meciar`s ruling coalition have defended the tax increase saying it would affect mainly those periodicals publishing pornography. The Finance Ministry had originally proposed a VAT rise on papers with at least 50 percent advertising content, saying this was compatible with European Union legislation, but this was overruled by the cabinet. Fuele said even this proposal was unacceptable, and that each price increase had always led to a drop in circulation. Last month the European Parliament called for a lowering or complete abolition of VAT on newspapers. In 1995, Mečiar tried to impose a substantial VAT increase on wholly or partly foreign-owned newspapers, but retreated in the face of a protest by independent newspapers which appeared with blank front pages the day after the move was announced.