Greece was downgraded in its debt rating to A2 by Moody'safter being cut by Fitch and S&P previously, which underscore concerns concerning the eligibility of the Greek debt which may be subject to another cut in March. Now, Greece has the highest debt deficit across the 16 nations using the euro.

The Greek government, however, has put a 4-year plan to lower budget deficit from 12.7% of GDP to 8.7% in 2010 and to reach less than 3%, which is the level set by the EU, by 2013. But, Greece may face a sever problem if the ECB made Greece's debt not suitable for the bank's repurchase operations.