Greek civil servants will strike again for 24 hours in March or April to protest against austerity measures aimed at tackling the country's worst financial crisis in decades, their union said on Monday.

Greece's government is under pressure from the markets and the European Union to implement deficit-cutting measures which include public sector salary cuts, tax increases and a pension freeze, but it faces union opposition.

"All these measures force us to decide on further powerful strikes either before or after Easter," Ilias Iliopoulos, General Secretary of ADEDY union told Reuters, adding the date of the strike would be decided later in the month.

The planned strike will be the union's fourth since the beginning of the year.

ADEDY, which will hold a rally in Athens on Tuesday, represents about 500,000 civil servants out of a total Greek labour force of 5 million.

Last week, a one-day national strike by public and private sector unions brought the country to a standstill but analysts said such protests were unlikely to change the government's fiscal consolidation plans.

POWER CORP

Workers at Public Power Corp, Greece's biggest electricity company, begin a 48-hour strike on Tuesday to protest against wage and pension cuts of at least 7 percent.

The state-controlled company's labour union, GENOP, will shut down some power plants but will stop short of disrupting power supply, its leader said.

"Some units will be taken offline but we don't wan

t a single light bulb to go out, at this stage," GENOP president Nikos Photopoulos told Reuters.

Although labour unions have threatened to step up protests, opinion polls show just over half of Greeks back the government's effort to cut a ballooning debt and budget deficit.

A survey published on Sunday showed 50.1 percent of those questioned believed the government's cutbacks are along the right lines while many said unions should be restrained in their opposition until the crisis is over.

EU politicians and ratings agencies say faultless execution of tax hikes and spending cuts will be crucial if Greece is to restore its credibility as a borrower and avoid further unsettling the single European currency.

Analysts are therefore watching for signs of growing unrest or opposition to the measures which are designed to tame a 300 billion-euro (274.9 billion pounds) debt pile and a swollen deficit.

Euro zone finance ministers gathered in Brussels on Monday to debate how to give Greece financial aid should it ask for help, something it has not yet done.