Senate Majority Leader Juan Miguel Zubiri cautioned his colleagues in the 23-member Senate on Tuesday to uphold the “history of this honorable chamber’’ by not using unparliamentary language.

Zubiri tried to cool down the heated debate between members of the Senate majority and minority blocs on the controversial C-5 road project.

Great men and women have “walked on the floor of this august chamber,’’ Zubiri said.

Ironically, “respondent’’ of the C-5 affair, Sen. Manuel Villar, continued to refuse to appear at the Senate to defend himself after being found guilty of unethical conduct on the alleged overpriced C-5 project.

Senator Richard J. Gordon, one of the three senators seeking the presidency through the May 10, 2010 national and local elections, advised his colleagues to be civil to one another by not using unparliamentary language “because the world and the country is looking at us.’’

He recalled that “we have a legislator in the past who was censured for unparliamentary language and this was Sergio Osmeña Jr.’’

Intemperate language should not be used, not even in the heat of passion, he added.

The debate became heated when Senate Minority leader Aquilino Q. Pimentel Jr. failed to delay the sponsorship speech of Senate President Juan Ponce Enrile, chairman of the Senate committee of the whole, on the committee report finding Villar guilty of unethical conduct.