Turkey is used to upheaval. From financial collapses to military coups to earthquakes, the country seems to endure more than its share of crises. But it has never before been faced with the scenario that will unfold today, when the 11 judges of the constitutional court begin deliberating on the most politically explosive case in the 46-year history of what is the country's highest legal body.

Abdurrahman Yalcinkaya, the chief prosecutor, has asked the judges to declare that the Justice and Development party (AKP), the populist, religiously rooted, socially conservative political movement that has governed Turkey for nearly six years, is "a centre of anti-secular activity" that is undermining the constitution and must be closed down. He also wants the judges to ban President Abdullah Gul, Recep Tayyip Erdogan, the prime minister, and 69 other party officials from party activity for five years.