Portuguese Prime Minister and leader of the Socialist Party Antonio Costa delivers a speech during a campaign rally in Lisbon, Portugal on Oct. 4, 2019. The Portuguese general elections will be held on Oct. 6, 2019. (Photo by Pedro Fiuza/Xinhua)

Leader of the Social Democratic Party (PSD) Rui Rio gestures during a campaign rally in Lisbon, Portugal on Oct. 4, 2019. The Portuguese general elections will be held on Oct. 6, 2019. (Photo by Pedro Fiuza/Xinhua)

Leader of the Social Democratic Party (PSD) Rui Rio (front L) waves during a campaign rally in Lisbon, Portugal on Oct. 4, 2019. The Portuguese general elections will be held on Oct. 6, 2019. (Photo by Pedro Fiuza/Xinhua)

Portuguese Prime Minister and leader of the Socialist Party Antonio Costa (front R) greets supporters with his wife Fernanda Tadeu (front) and Mayor of Lisbon Fernando Medina (front L) during a campaign rally in Lisbon, Portugal on Oct. 4, 2019. The Portuguese general elections will be held on Oct. 6, 2019. (Photo by Pedro Fiuza/Xinhua)