HARARE, March 5 (Xinhua) -- A new political party believed to have the support of former President Robert Mugabe has been formed in Zimbabwe to challenge President Emmerson Mnangagwa's ruling ZANU-PF party in elections set for mid-2018.

In a statement issued on Monday, the New Patriotic Front (NPF) announced the appointment of Ambrose Mutinhiri as party leader and presidential candidate for the polls.

Mutinhiri, a retired brigadier general and seasoned liberation war fighter, resigned from ZANU-PF and Parliament last Friday to protest what he called the "unconstitutional removal of Mugabe" from power.

He once served as a minister in Mugabe's government.

Mugabe resigned in November last year after a military intervention and was replaced by President Emmerson Mnangagwa who he had sacked two weeks earlier amid intense infighting in the party over his succession.

Mutinhiri's resignation came a day after he paid a courtesy call on Mugabe at his residence in Harare to brief him about his latest initiative.

"The purpose of the courtesy call was to apprise President Mugabe of Cde. Mutinhiri's bold and inspiring resignation as well as to thank the President for having afforded Cde. Mutinhiri a cherished opportunity to work with and under him in various national capacities," said a statement issued by political activist and former journalist Jealousy Mawarire.

Mawarire said that during the meeting, Mutinhiri thanked Mugabe "for laying a solid and irreversible ground for generational renewal in parliament and government through progressive policies that have empowered the youth who are now poised for unstoppable leadership roles across the political divide and in business, civil society and churches."

Mugabe congratulated Mutinhiri for taking a bold move and said that Zimbabwe needs men and women of principle who should fight to preserve the legacy of the liberation struggle legacy, Mawarire said.

Mugabe, Mawarire added, urged Mutinhiri to work closely with the full spectrum of the youth to enable them to take over the governance of the country in the interest of generational renewal.

"I hope your NPF party will empower the youths to take over," Mugabe was quoted as telling Mutinhiri. "Don't oppress them. Make sure they are not harassed. I know they will be harassed and some arrested but empower them mentally to fight for what is right."

Members of the G40 faction and self-exiled former cabinet ministers Patrick Zhuwao and Jonathan Moyo have been the leading public faces of the NPF before the announcement of Mutinhiri as party leader.

The new opposition party says its ideals revolve around upholding the values and democratic ideals of the liberation struggle, preservation of the historic land reform and empowerment policies.

The NPF said it was approaching the Constitutional Court in Zimbabwe as well as appropriate regional, continental and international bodies to challenge the legality of the new government.

The government of President Mnangagwa has since its formation last December received national, regional, and global recognition.