Iraq’s beleaguered prime minister defied calls for his resignation last night and deployed special forces around Baghdad, accusing the country’s president of mounting a coup.

Nouri al-Maliki, a Shia leader who has been widely blamed for exacerbating the country’s sectarian tensions, made a surprise appearance on television to announce that he was suing President Massoum’s for violating the constitution. As he spoke , troops loyal to Mr al-Maliki seized key positions around the capital, including the Green Zone, the seat of the government.

The move was sparked by President Massoum’s refusal to name the new prime minister by last night’s deadline. As acting prime miknister andf leader of the largest block in parliament, Mr al-Maliki lays claim to the job, but most Sunnis and Kurds,