* New austerity steps to be discussed
* Package to have common, not different terms for EU/IMF
* Juncker says euro zone money is there if needed
* Spreads hit euro era record high
(Adds PM comment, Soros, protest, strike)
By Michael Winfrey and George Georgiopoulos
ATHENS, April 19 (Reuters) - Greece could face pressure to take tougher austerity measures when European and IMF officials discuss an aid package this week, a senior EU official said, as a delay in the talks pushed Athens' borrowing costs to new highs.
The euro zone member hopes to begin talks with the mission on Wednesday on a policy programme that investors are increasingly sure will lead the debt-ridden country to tap the biggest bailout ever attempted.
Originally scheduled for Monday, the meetings were delayed by a volcanic ash cloud that has wreaked havoc with transport across Europe, adding to investor uncertainty, pushing up Greek bond yields and bank shares down.
Greece has already cut public sector wages, frozen pensions, and raised taxes to try to cut its budget deficit by around a third to 8.7 percent of GDP this year.
Eurogroup Chairman Jean-Claude Juncker told Greek financial website Euro2day the measures for 2010 were "pretty ambitious and look credible" but said there could be more after talks with the European Central Bank, the European Commission, and the IMF.
"During our talks with the troika on the Greek package, the possibility of new measures will be discussed," he was quoted as saying in the interview, published in Greek and translated back into English.
The Mediterranean country of 11 million has yet to ask for activation of the EU/IMF aid safety net, estimated at 45 billion euros ($62.91 billion) in the first year.
The government refused to comment on Juncker's statements, but Finance Minister George Papaconstantinou had scheduled a news conference for 0900 GMT on Wednesday.
"These talks are very important because they will make it possible for us to move very fast if the Greek government decides on the activation of the mechanism," he said.
Greek Prime Minister George Papandreou told a cabinet meeting the mechanism was there to ensure to make sure the country can move forward.
"If the country's interests require us to activate the support mechanism we will do it without hesitation," he said.
"DEATH SPIRAL"
But the prospect has raised anxiety among Greeks fearing more austerity. About 200 workers rallied outside the finance ministry holding banners reading "IMF Go Home" and the head of the employers' association predicted more harsh cuts.
Polls show that, although still supporting the government, most Greeks opposed austerity measures and unions have announced strikes. On Thursday, civil servants will hold a strike for 24 hours to protest the belt tightening, their fourth this year.
"The IMF will certainly demand new measures for 2010," Vassilis Korkidis, president of Greek Confederation of Trade, told Greek radio. "The strategy of domestic deflation will plunge us further into recession."
Persistent confusion over how the deal would work and doubts over Greece's long-term solvency have spooked investors.
The premium demanded to hold Greek bonds rather than German benchmarks rose to a euro era record of 482 basis points on Monday, up about 40 basis points from Friday's close and far over the 2008 pre-crisis levels of about 50 or 60 basis points.
The cost of protecting Greek government debt against default rose to a record high, according to monitor CMA DataVision.. Bank shares fell 2.6 percent.
Billionaire financier George Soros said the interest rate of 5 percent insisted upon by Germany for the euro zone's part of the deal could hurt Greece by causing more budget cuts, deeper recession, and lower budget revenues.
"Then it becomes a vicious cycle," he said. "I would call it a death circle. That's really the danger."
Germans oppose helping Greece ahead of a May 9 election. Berlin has resisted giving the deal a green light and says it could encourage countries that flout EU budget rules.
"MONEY IS THERE"
Some IMF officials had already arrived in Athens on Monday, but Greek officials are expected to wait for members of the other institutions before starting talks.
In Brussels, a spokesman for the European Commission said the officials could potentially hold a video conference. The IMF has said the mission should last 15 days and any agreement would be finalised shortly afterward by its board.
Juncker said the plan would be on common terms, rather than having some IMF benchmarks and others for the European bodies.
"In no way will there be different terms from the euro zone and other ones from the IMF," he said.
Greece says it must raise roughly 12 billion euros in May to refinance debt, make bond interest payments, and finance its deficit, and it will face a test on Tuesday in a sale of 1.5 billion euros in short-term debt.
Juncker said one major problem was that it appeared markets did not trust the euro zone to step in and help Greece if it were to request financial aid. He said this was not true.
"What I must say is that the euro zone will assume its responsibilities. We have said it many times, there is European money when it becomes necessary," he was quoted as saying. (Additional reporting by Harry Papachristou and Renee Maltezou; editing by Stephen Nisbet, Ron Askew)