political football

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun countable, idiomatic A contentious political issue or problem that is often debated or discussed, but that remains unresolved; an issue or problem which is avoided by authorities and handed off to others.
• noun uncountable, idiomatic Ongoing unproductive wrangling or posturing between political factions, resulting in failure to deal with an issue or problem in a decisive or appropriate way.