[JURIST] Thai Prime Minister Thaksin Shinawatra [official profile] announced Saturday that Thailand [government website] will hold a national referendum on whether to amend the nine-year-old Thai Constitution [text] April 19 in conjunction with the country's next Senate election. Thaksin, who has faced recent calls for his resignation, made the announcement prior to an anti-government demonstration expected to draw tens of thousands of protestors. Publisher Sondhi Limthongkul [Wikipedia profile], a vocal opponent of the Thaksin government, organized Saturday's rally after a similar demonstration last weekend drew 60,000 protestors. Critics of the 1997 constitution claim it has permitted the ruling governmental party to amass power despite its initial intent to promote democracy. AP has more. Reaction in Thailand to the announcement has so far been distinctly mixed [Bangkok Post report].