HARARE (Reuters) – A new party founded by Zimbabwe’s former vice president Joice Mujuru suffered a crushing defeat in its first ever election contest again President Robert Mugabe’s ruling ZANU-PF, showing the task she faces in her bid to challenge her ally-turned-adversary.

ZANU-PF retained the rural Bikita West parliamentary constituency in Saturday’s by-election after its candidate polled 13,156 votes against 2,453 votes for Mujuru’s Zimbabwe People First, the Zimbabwe Electoral Commission said on Sunday.

Mujuru, Mugabe’s deputy for 10 years, was seen as the most likely successor to the 92-year-old leader until she was purged from the ruling party in 2014 after charges she was plotting against Africa’s oldest leader. Mujuru denies the charges.

Mugabe has ruled the former British colony since independence in 1980. He turns 93 on Feb. 21 and has been confirmed as the ZANU-PF presidential candidate for the vote which is due in 2018.

Last year Mujuru formed her own political party to challenge Mugabe, raising hopes that a politician who had liberation war credentials and enjoyed the support of some military generals could successfully challenge Mugabe.

The poor showing in Bikita West, which was marked by high voter turnout, comes at a time Mujuru is negotiation with the main opposition Movement for Democratic Change (MDC) on a coalition pact to take on Mugabe in next year’s election.

The MDC led by Morgan Tsvangirai did not contest Saturday’s vote in keeping with its decision to boycott all elections because it argues the election environment favours the ruling party.

ZANU-PF is the dominant party in parliament where it has 221 out of 270 seats in the lower house.

Mujuru could not be reached for comment on Sunday. Her spokesman Jealousy Mawarire said he could not immediately comment.

(Reporting by MacDonald Dzirutwe; Editing by Keith Weir)