One hundred Portuguese business leaders have signed an open letter expressing concern about the country's ongoing political uncertainty and warning it could hurt the economy if it goes on much longer.

With Portugal's new government barely a week old and larger opposition parties vowing to force its resignation within days, the letter published Friday said the uncertainty is jeopardizing a fragile economic recovery.

The letter's signatories, who lead some of Portugal's biggest companies, said the political climate is a threat to their investment and hiring plans.

Portugal's center-right government is due to present its policy program in a two-day parliamentary debate starting next Monday. Three left-of-center parties, who together have more votes than the government, say they will unite to force its resignation by rejecting the program.