President Recep Tayyip Erdogan yesterday celebrated winning five more years in office with sweeping new powers after a decisive election victory, as Turkey's opposition raised bitter questions over the conduct of the polls.

A night of triumph for Erdogan saw the man who has dominated Turkey for the last one-and-a-half-decades declared winner of Sunday's presidential polls without needing a second round and lead his ruling party-led alliance to an overall majority in parliament. Erdogan, whose victory was wider than predicted by many analysts, immediately vowed to "rapidly" implement the new presidential system agreed in an April 2017 referendum that opponents fear will give him autocratic powers.