Opening the National Museum on Mondays, including bank holiday Mondays, would cost between £90,000 and £300,000 a year, the Minister for Arts told the Dail.
Opening on bank holiday Mondays would cost £6,000 extra each day, Ms de Valera said, and extending opening times at the museum by two hours on a Sunday would cost £63,000 a year. Late opening for an extra three hours one night a week would cost about £70,000 a year.
Ms de Valera said extending opening hours would have major "financial, organisational and staffing implications" for the National Museum.
Proposals for extended opening hours would be considered "in the context of the resources available to me in this Department".