Cyprus's parliament will decide on Sunday whether savers must pay a levy on bank deposits under terms for an international bailout to avert bankruptcy - with approval far from certain.
The euro zone demand on Saturday that savers pay up to 10 percent of deposits as a condition for the 10 billion euro ($13 billion)
Newly elected Cypriot President Nicos Anastasiades said refusing the bailout would have led to the collapse of the island's two largest banks, badly singed by their exposure to bailed out neighbour Greece.
The tax on deposits in Cyprus, which accounts for only 0.2 percent of the euro zone's economy, is expected to raise up to 6 billion euros as a condition for the bailout, mainly needed to recapitalise banks.
Those affected will include rich Russians with deposits in Cyprus and Europeans who have retired to the island as well as Cypriots themselves.
The size of foreign deposits in Cyprus - estimated at 37 percent of the total - was one reason the euro zone agreed to the tax on savings, to take effect when banks reopen on Tuesday. Cyprus stopped electronic transfers over the weekend.
In Spain, one of four other states getting euro zone help and seen as a possible candidate for a sovereign rescue, officials were quick to say that Cyprus was a one-off. A Bank of Spain spokesman said there had been no sign of deposit flight.
Two Cypriot banks in Britain told savers their money was safe.
Cyprus's parliament was due to convene at 4 p.m. (1400 GMT) in an emergency session to discuss the proposed penalties on deposits: 9.9 percent for those exceeding 100,000 euros and 6.7 percent on anything below that.