Leftist candidate Hamdeen Sabahi will appeal for Egypt's presidential election to be suspended citing alleged voting irregularities and a pending case over one of the frontrunner's right to stand.

Sabahi's pledge to pursue a suspension came as the two apparent winners of the first round, the Muslim Brotherhood's Mohammed Morsi and Ahmed Shafiq, a former prime minister under Hosni Mubarak, reached out to rival candidates ahead of a June runoff.

Al Jazeera's Jamal el-Shayyal reports from Cairo.