The bill was labeled by Sri Lanka's main opposition United National Party as a move that will hurt "the cultural, social and religious interests," of the country by the de facto creation of 'redlight' districts.
Some of Sri Lanka's existing casinos are used as pick-up points by commercial sex workers, especially non-national ones, who also cater to the tourist trade.
The UNP itself drew criticism from sections of the current ruling coalition for planning a law to legalize 'redlight' districts shortly before it was thrown out of power in 2004.
The posturing is typical of the widespread hypocrisy and deceptive 'politicking' that is practised on the people by all politicians in the island.
Sri Lanka is planning to attract several million tourists to the island after a 30-year war ended last year.
Tourists who frequent casinos are usually high spenders. Several Asian nations including Malaysia has designated areas where gambling is legal.
The bill to regulate casinos was passed with