Thousands of Greeks marched on Parliament on Saturday in a show of public anger after Prime Minister George Papandreou vowed to push on with an austerity campaign that a poll showed half the country opposed.

In a move meant to stifle dissent in his Socialist Party, Papandreou on Friday dismissed Finance Minister George Papaconstantinou, architect of a new five-year austerity program that has sparked weeks of protests.

The reshuffle coincided with a pledge by France and Germany to continue funding Athens, a move that may have bought Greece and its fellow euro-zone members time to prevent a messy default, even if doubts over its longer-term solvency persist.

The European Union and International Monetary Fund have made reforms a condition for a new bailout package worth an estimated $170 billion that Greece, shut out of markets, will need to fund itself through 2014.

About 5,000 protesters from the Communist group PAME marched into Athens’s central Syntagma square — where demonstrations turned violent last week — chanting, “The measures are killing us!”

An opinion poll taken before the reshuffle showed 47.5 percent of respondents wanted Parliament to reject the reform package and for Greece to hold early elections. Just over a third — 34.8 percent — wanted it to be approved so that the government could secure the second bailout.

Constantinos Routzounis, head of pollsters Kapa Research, said Greeks were not against austerity but thought the reforms were unfairly aimed at the poor while wealthy tax evaders and corrupt politicians got off lightly.

“People don’t want Greece to exit the euro zone,’’ he said. “They do want fiscal consolidation measures — but more-just ones.’’

Greece’s biggest union, GSEE, representing about 2 million workers in the private sector, called for a 48-hour strike when Parliament votes on what has been dubbed the midterm plan. The government hopes that will happen by the end of the month.

Papandreou appeared to curb a revolt in his party by including some of the austerity package’s harshest critics in the new administration, but that might also lead to a weakening of the reforms.

He named political heavyweight Evangelos Venizelos, his biggest party rival, as finance minister. Venizelos said he would travel to Luxembourg on Sunday to meet euro-zone finance ministers and ask them to allow some “improvements . . . for social justice” in the reforms. fueling concerns that the new government has less resolve to hammer through the austerity program.

— Reuters