The tax, a form of inheritance tax dropped in 2008, brought 2.1 billion euros ($2.96 billion) to government coffers in 2007 but was abandoned as part of the Socialists' efforts to stimulate the economy as Spain slipped in to recession.

No one in the economy ministry was immediately available for comment on the report.

Since 2008 prolonged economic stagnation has turned a public sector surplus into one of the euro zone's largest deficits and forced the government to pass measures to reduce the shortfall and prove it had control of its finances.

Prime Minister Jose Luis Rodriguez Zapatero appears in Parliament on Tuesday to defend his latest round of measures to save around 5 billion euros to shore up this year's deficit target amid concerns of overspending by the country's regions. ($1=.7099 Euro)

Copyright Reuters, 2011