Sanader voiced his support by videolink as the coalition, which is comprised of the HDZ 1990 party and four similar conservative parties, held a pre-election convention in the southern Bosnian city of Mostar.
"I wish you electoral victory," said Sanader, adding that the upcoming elections were crucial as they would provide Bosnian Croats with an opportunity to affirm their role as a constituent, sovereign people equal to the other peoples in the country.
"The Republic of Croatia and Bosnia and Herzegovina are friendly countries. We wish Bosnia and Herzegovina well but this will not be easy unless the Croat people remains constituent, equal and sovereign. We wish to develop good relations with Bosnia and Herzegovina also in this sense," said Sanader.
He called on other Bosnian Croat parties to join the coalition in order to realise the strategic interest of securing the Bosnian Croat people's status so that it would not come into question again.
Sanader said Croatia would do everything in its power for Bosnia to draw closer to the European Union with the as yet unsigned Stabilisation and Association Agreement, and to draw closer to NATO via Partnership for Peace.
"Bosnia and Herzegovina's European future and Euro-Atlantic integration must be the common interest of all peoples in Bosnia as this will guarantee Bosnia's future," said Sanader.
Addressing the convention, a deputy speaker of the Croatian parliament and a member of the HDZ Presidency, Luka Bebic, called on Bosnian Croat officials to forget personal interests at the forthcoming polls as now was the time when the fate of the Bosnian Croat people was being settled.
The HDZ delegation at the convention was led by the party's secretary general Ivan Jarnjak. He and Bebic told the press afterwards they had come to support the Croatian Unity coalition and not impose Zagreb's policy towards Croats in Bosnia.
"Croats will lead their policy through Bosnia's institutions. Sanader won't influence that policy and Bozo Ljubic must win the confidence of the international community by himself, just like Sanader did," said Jarnjak.
In his address at the convention, Ljubic advocated organising Bosnia and Herzegovina as a federation in a way to guarantee the equality of the Croats. He outlined three possibilities -- Bosnia comprised of three entities with discontinuity of territory (noncompact territory), Bosnia comprised of four regions, or cantonisation.
Attending the convention were several Croatian members of parliament, a delegation of the Croatian Peasant Party and Croatian Ambassador Josip Vrbosic.
In a telegram of support, the primate of the Catholic Church in Bosnia, Cardinal Vinko Puljic, said: "Let's not let others make us quarrel and divide us". He urged Bosnian Croats to go to the polls saying that not going meant voting for those against the sovereignty and equality of Bosnian Croats.
Cardinal Puljic also called on Bosnian Croat politicians not to fight for personal but Croat interests and for the common good.