Tosefta for Pesachim 97:18

[If] the fourteenth [of Nissan] falls on the Sabbath, we remove everything [containing chametz] before the Sabbath begins, and bake matzah for it (i.e., for Passover) up until Sabbath Eve. Pure and impure Terumah: We remove them before Sabbath begins, the words of Rabbi Meir. And the Sages say, [they are removed] at their [customary] time. Pure and impure Terumah are removed on the Sabbath. Said Rabbi Elazer bar Rabbi Tzaddok, Terumah [is removed] before the Sabbath since few eat it, and chullin on the Sabbath since many eat it. Said Rabbi Elazer bar Rabbi Tzaddok, one time we were sitting before Rabban Gamaliel in the study hall in Lod [during a year when Passover fell on the Sabbath, see Pes. 49a:2] and in came Zunin, the deputy [of Rabban Gamaliel], and he said, "The time has come to remove the chametz!" My father and I want to the house of Rabban Gamaliel and we removed the chametz [even though it was the Sabbath].