The Hebrew word for strong, "hazak", peppers the television adverts of his right-wing Likud-Yisrael Beiteinu party like a compulsive mantra and is smeared across the blue-and-white campaign posters that dominate billboards around the country.

Robust leadership is vital, Netanyahu says, to deal with his generation's biggest challenge - not the decades-old conflict with the Palestinians, but fears that Iran is bent on building an atomic bomb that could one day target the Jewish state.

"My priority, if I'm elected for a next term as prime minister, will be first to stop Iran from getting nuclear weapons," Netanyahu told a delegation of U.S. senators who visited him in Jerusalem on January 11.