A proposed constitutional amendment that would force Spain's government to keep its deficit low cleared its first hurdle in Parliament on Tuesday.

Lawmakers in the lower chamber voted to debate the amendment and vote on it Friday. The tally was 318 in favor, 16 against and two abstentions. The result was expected because the amendment is supported by both main parties, the ruling Socialists and opposition, center-right Popular Party.

Once the bill is passed, it goes to the Senate next week.

The goal of the amendment is to enshrine budgetary discipline in the constitution and reassure markets that economically struggling Spain will keep its state finances under control.

Spain is fighting to recover from nearly two years of recession prompted largely by the collapse of a real estate bubble and a credit-fueled consumer spending spree. The jobless rate is near 21 percent, almost 45 percent for young people, and economic growth remains anemic.

Spanish bond yields, a direct measure of how jittery investors are about a country's debt, soared to record levels early this month, and came back down only after the European Central Bank intervened and bought billions in Spanish bonds on the secondary market.

In Tuesday's debate, Socialist party spokesman Jose Antonio Alonso said the constitutional amendment was the best way to dispel doubts over Spain's solidity and reliability. "Spain pays its debts and there should be no doubt about this," Alonso
said.

The amendment enshrines the principle of budgetary discipline into Spain's constitution, but does not specify numbers. These will come in a separate law that is to be passed by June 2012. The two main parties have agreed the law will stipulate that Spain's deficit cannot be exceed 0.4 percent of GDP but this threshold will not take effect until 2020.

Labor unions say Spain is caving into market pressure and have convened street rallies to protest the amendment. The main one will be next week in Madrid.