Joice Mujuru, a former vice-president of Zimbabwe and current leader of the opposition party Zimbabwe People First (ZimPF), has warned that her party would expose alleged wrongdoings by President Robert Mugabe in a provocative new book.

Once a powerful ally of Mugabe, Mujuru was sacked from the ruling Zanu-PF party in 2014 after accusations emerged that she was plotting to kill the president, but she returned to politics this year with the launch of ZimPF. Described as a reformist, Mujuru is now seen as a true contender for leadership in the 2018 elections, while commentators have highlighted how her 10-year stint as Mugabe's deputy has enabled her to cultivate a strong support base within the party.

Mujuru's party is this week due to release a book, The National Grievances, written by war veteran and ex-Zanu PF official Kudzai Mbudzi.

Describing how ZimPF was not scared of exposing the president's failings, local newspaper The Standard has reported Mbudzi as saying: "[The] book will be giving a detailed account of national grievances against Mugabe".

Zanu-PF under attack from opposition

ZimPF has made several attacks on the Zanu-PF. Earlier in May 2016, it alleged to have undisclosed information on how Zanu-PF rigged polls particularly the contested 2008 and 2013 general elections.

Speaking about the new book, Mbudzi said it would "expose [Mugabe's] failures in all the facets of our lives. The book will look at how Mugabe destroyed education in this country, high levels of unemployment, the collapse of industry, deterioration of infrastructure, poor road network and how he is creating sex workers out of very innocent people, how he destroyed the economy and all other sectors in Zimbabwe."

Some 2.5 million Zimbabwans are starving

Gripped by drought, Zimbabwe could also be on the verge of total economic collapse after 36 years under Mugabe's rule. In February, Zimbabwe appealed to domestic and international backers for assistance as it revealed that more than a quarter of its population was going hungry – 2.5 million of its people – following a declaration of a state of disaster by Mugabe.

In 2015, Global Finance Magazine placed Zimbabwe second-poorest after the Democratic Republic of Congo in its survey of 184 countries.

Some estimates put the rate of unemployment at 95%, but official figures are never revealed. Based on IMF data, the survey showed Zimbabwean's average annual income between 2009 and 2013 was around $589 (£410). In contrast, South Africans earned more than $11,000 a year (£7,600), on average.

Two women in a railway waiting room in Harare beneath the ubiquitous portrait of president Robert Mugabe Mary Turner/Getty