Up to $60 million stems from local taxes and the rest from "gifts and outside assistance," said legislator Jamal Nassar. Iran is believed to be one of Hamas' main financial backers, with cash assistance hauled through smuggling tunnels under Gaza's border with Egypt.
Nassar and fellow lawmaker Yehia Moussa refused to provide a detailed breakdown of the spending plan, and it was impossible to verify that Hamas indeed has $540 million at its disposal.
However, a border blockade by Israel and Egypt - first imposed in 2006 and tightened after Hamas overran Gaza a year later - has not weakened the militants. With only humanitarian aid and a few basic items entering Gaza through border crossings, the tunnels are the main supply line for cash, weapons and a wide range of commercial goods.
The Hamas government has about 32,000 people on its payroll, including civil servants and members of the security forces. About $30 million of the budget would go to Arab residents of Jerusalem and Islamic sites in the city, Nassar said, without explaining how the money would reach its destination.
The budget was passed by parliament Thursday, without an immediate announcement.
In adopting a separate spending plan, Hamas further cemented the rift with the West Bank, run by Palestinian President Mahmoud Abbas. Hamas seized control of Gaza in 2007, leaving Abbas' rival Fatah movement in charge only of the West Bank.
Palestinians want both territories, which flank Israel, to become their future state.
The Abbas government's budget for 2009 was $2.78 billion, funded in large part by foreign aid. Abbas' Palestinian Authority continues to pay the salaries for tens of thousands of Gaza civil servants and security officers who were sent home after the Hamas takeover. It also pays for fuel to run Gaza's power plant and supports hospitals and schools.
The Hamas government is also relieved of much responsibility because the United Nations runs dozens of schools, health clinics and gives food aid to around 1 million Gazans.