The result of the referendum that grants sweeping new powers to the president of Turkey is valid, the head of the electoral body says. <br />Sadi Guven was speaking after the main opposition Republican People's Party (CHP) cited irregularities, including the use of unstamped ballot papers. <br />President Recep Tayyip Erdogan's push for an executive presidency succeeded with just over 51% of the vote. <br />The win was met with both celebrations and protests across Turkey. <br />The CHP has demanded a recount of 60% of the votes. <br />But Mr Guven told reporters on Monday the unstamped ballot papers had been produced by the High Electoral Board and were valid. <br />He said a similar procedure had been used in past elections. <br />Three of Turkey's biggest cities - Istanbul, Ankara and Izmir - all voted No to the constitutional changes. <br />Opposition supporters took to the streets of Istanbul to bang pots and pans - a traditional form of protest - in a series of noisy demonstrations.
