In his visit to Akkar and Dinniyah, some 60 miles north of Beirut, on Tuesday, Hariri was seeking to encourage people to vote in large numbers on 19 June 19, when northerners choose their 28 legislators in the final phase of four-stage parliamentary elections.
Al-Hariri - whose father, former prime minister Rafik al-Hariri, was assassinated in February - is backing a ticket that includes members of his Future Movement and the Lebanese Forces, the main Christian militia during Lebanon's 1975-90
Meanwhile, in the coastal town of Byblos, Christian leader and former army commander Michel Aoun named the ticket he is heading in Kesrwan-Byblos, part of the central Mount Lebanon region that votes next Sunday.
Mount Lebanon is pivotal as it is the country's most populous province. It has 35 seats in the 128-seat parliament and some are referring to the vote as "the Mother of all Battles" because of the strong contenders vying for seats.
Aoun's main opponent, Druze opposition leader Walid Jumblatt, has already won uncontested in his Chouf district of Mount Lebanon.
Aoun is also expected to win a seat.
Saad al-Hariri: We can only know
the truth through your votes
The decisive battle between their two factions will be in Baabda-Aley, a mountainous and coastal constituency with a mix of Christian, Druze and Shia voters.
Elections will be also held on Sunday for 23 seats in the eastern Bekaa Valley.
In Akkar, Saad al-Hariri stood along with candidates running on the National Unity ticket, including Setrida Geagea, wife of jailed former Lebanese Forces leader Samir Geagea.
"Every vote you will cast is a strike and a bullet in the hearts of the criminals who killed Rafik Hariri," Saad al-Hariri told thousands of supporters in Dinniyah earlier.
"We can only know the truth through your votes."
Saad al-Hariri's ticket won all 19 seats up for grabs in Beirut on 29 May, the first phase of the polls. On Sunday, the Hizb Allah group and its allies crushed all their opponents in southern Lebanon to win all of the region's 23 seats.
Competition is expected to be tough in the north between pro and anti-Syrian candidates.
The Hizb Allah-Amal alliance has
swept the South Lebanon vote
The elections are the first national polls to be conducted since Syria withdrew all its troops from Lebanon in April under intense international pressure, particularly following al-Hariri's assassination.
Lebanon's 128-member parliament is equally divided between Christians and Muslims
However, the electoral alliances of pro- and anti-Syrian groups have become so intermingled that sometimes it is hard to explain who is running against whom.