Businesses will only invest in Greece if three conditions are fulfilled. First, there must be a clear commitment to the euro. No businesses will invest if they have to fear that Greece will leave the euro zone at some point. Second, the Greek government must be prepared to work together with European institutions in order to restructure the country.

Referendums are a democratic instrument, but so are decisions reached in a parliamentary democracy. I advise extreme caution when it comes to referendums. In Germany too.

My mother's brother was killed while clearing mines in 1945. Those are things that mark your childhood and they help explain why we are so devoted to European unity.

We must now, in the 21st century, protect democracy, one which rests on fundamental rights for all, regardless of skin color, gender, race or religion. Nothing less than that is at stake.

We are seeing now that without the contribution of the Social Democrats, Germany cannot be governed. We are a proud and self-confident party. We should now act based on that pride, and not out of fear.

I want to end tax dumping. States that have a common currency should not be engaged in tax competition. We need a minimum tax rate and a European finance minister, who would be responsible for closing the tax loopholes and getting rid of the tax havens inside and outside the EU. It is also clear that we have to reach common standards in our economic and labor policies. We cannot continue to just talk about technical details. We have to inspire enthusiasm in Germany for Europe.

We have committed ourselves to pursue joint policies, but then national governments say, "We aren't bound by that." That is a dramatic situation, because solidarity is a basic principle that cannot be had on an à la carte basis. If we have rules that nobody adheres to, then the community will break apart.