When can the European Commission trigger Article 7? | DW Englisch

The European Commission is taking up the question of whether to trigger Article 7 and impose sanctions against Poland, which could mean suspended voting rights and cuts in EU aid. But when can Article 7 be invoked, and how difficult is the process?

For more go to http://www.dw.com/en/eu-threatens-to-trigger-article-7-for-poland/a-41869331