S&P downgrades France, Spain, Italy, Austria.

Countries could be downgraded based on results of this week's EU summit.

Rating agency expected to issue negative outlook on all 17 countries.

Rating agency expected to issue negative outlook on all 17 countries.

Countries could be downgraded based on results of this week's EU summit.

German chancellor argues against using central bank as crisis backstop.

German chancellor argues against using central bank as crisis backstop.

Dispute centers on the ECB's role in the rescue plan.