Updated

Two major opposition figures in Zimbabwe have signed a pact pledging to work toward establishing a united front to challenge President Robert Mugabe in next year's elections.

Morgan Tsvangirai, whose MDC-T party is the biggest opposition in parliament, and Joice Mujuru, a former vice president, described the memorandum of understanding as a significant step in their efforts to form a coalition.

The memorandum of understanding signed Wednesday is a sign of the two political parties' desire to explore the possibility of working together in their bid to unseat the 93-year-old Mugabe.

Mugabe has said he will contest the election. He has been in power since the end of British colonial rule.

He fired Mujuru in 2014, accusing her of plotting to unseat him. She now leads her own party.