The euro zone has only small internal transfers, and its workers tend not to move far for work.

ECONOMIST: Charlemagne

The euro zone is showing the symptoms of an internal balance-of-payments crisis, with self-fulfilling runs on countries, because at bottom that is the nature of its troubles.

ECONOMIST: The euro

The Greek crisis only confirms the folly of binding a group of disparate countries together in a currency zone with no mechanism, such as a central fiscal authority, to address its internal imbalances.

ECONOMIST: Greece's sovereign-debt crunch

Perhaps even more importantly, Mr. Almunia is working with his colleagues Olli Rehn his successor in the economic and financial affairs post and Internal Market Commissioner Michel Barnier to present a proposal for a new banking supervisor for the euro zone straight after the summer.

WSJ: Economics Guru Jumps

Whitehall sources argue that Mr Cameron has already secured a written vow by the 27 leaders that euro-zone deals may not undermine an achievement dear to Tory hearts the EU's internal market, with its free movement for capital, goods, people and services (at least in theory).

ECONOMIST: Bagehot