ATHENS: The Greek parliament has adopted a crisis budget for 2010 in a bid to bring order to its chaotic public finances and restore its badly dented credibility with foreign investors and the European Union.

The budget, passed by a healthy majority in the single-chamber parliament late Wednesday, is marked by a reduction in the public deficit from 12.7 percent of output in 2009 to 9.1 percent.

The 160 Socialist Pasok deputies in power since October voted for the budget, and 139 opposition members including conservatives, communists, the radical left and extreme right voted against. One conservative member was absent.

Wrapping up five days of debates, which came as Greece's debt has soared bringing a drop in its credit ratings, Prime Minister George Papandreou said the budget was "a contract to reconquer our credibility."

Papandreou went on: "We shall prove our capacity and determination to change this country, to ourselves and to any foreigner who puts in doubt our will."

The Socialists, elected in October on an economy rescue ticket, had already warned that the 2010 budget was the nation's "toughest" since the restoration of democracy in 1974 after seven years of military rule.

The government is struggling to restore investor confidence and muster funds to service an estimated 300-billion-euro debt following three successive downgrades from international credit rating agencies this month.

The budget aims to reduce the deficit from 12.7 percent of output to 9.1 percent in 2010, which would still exceed the limit of 3.0 percent for countries that use the single European currency.

But the government has already promised to aim for a bolder deficit cut to 8.7 percent of output next year.

Under the budget the debt will in fact rise to 120.8 percent of GDP compared to 113.4 percent for 2009.

Expenditure will fall back by 2.3 percent while income is slated to rise by nine percent over 2009.

Tax revenue is expected to be up due to a tougher fight against fraud while public spending will be cut essentially through cutting back on waste. The defence ministry's budget is down 6.6 percent over 2009.

GDP is expected to stagnate in 2010 with a drop of 0.3 percent, showing a slight improvement over 2009 when a drop of 1.2 percent is expected. Inflation is forecast at 1.4 percent against 1.2 while unemployment would continue to rise, to 9.7 percent against nine percent in 2009.

Public coffers face a major drain from state hospital debts -- estimated at 6.3 billion euros -- and pension funds sapped by Greece's aging population and widespread social contribution avoidance.

"Unless this course is checked we'll need loans in May to pay pensions and other benefits," deputy labour minister George Koutroumanis told deputies.

The government also plans to borrow up to 53 billion euros in 2010 and expects to fork out 12.95 billion euros -- or 5.3 percent of output -- in interest payments next year to service the debt.

The Socialists pledged to cut waste in the bloated Greek civil service and public sector and boost revenue through a crackdown on entrenched tax evasion.

But the markets have shown little inclination to wait for reforms that successive Greek governments have promised yet failed to implement.

And Greece's European Union peers are also losing patience with Athens, which revised crucial economic figures twice in the last five years.

"Our credibility deficit is more important than the deficit in our public finances," Finance Minister George Papaconstantinou told parliament this week.

"People just don't believe us. 'We've heard the same talk for five years', they say," the minister added.

Fears for Greece's ability to keep up with its massive debt mounted this month after a solvency scare in the once-flourishing Gulf emirate of Dubai.