FACTBOX: Major parties in Zimbabwe elections

(Reuters) - Following is a factbox on the major parties contesting Zimbabwe's elections:

ZANU-PF

In power since independence from Britain in 1980.

Formed in 1964 during white minority rule, and one of two parties that led the struggle for independence.

Merged with Joshua Nkomo's PF-ZAPU in 1987 after a five-year political rebellion in ZAPU's Matabaleland and Midlands strongholds.

Robert Mugabe has led ZANU-PF for over 30 years.

ZANU-PF won 62 of the 120 contested seats in the last general parliamentary elections in 2000 which were marred by violence and rejected as fraudulent by the opposition.

Mugabe says ZANU-PF -- which had a two-thirds majority in the last parliament elected on March 31 2005 -- must win this year's polls overwhelmingly to shame its Western critics.

MOVEMENT FOR DEMOCRATIC CHANGE (MDC)