Supporters cheer as Joao Lourenco, presidential candidate for the ruling MPLA party, speaks at an election rally in Malanje, Angola. Picture: Reuters/Stephen Eisenhammer

Luanda - Angolans headed to the polls on Wednesday in a parliamentary election expected to usher in the ruling party's defence minister as the first new leader of Africa's second biggest oil producer for 38 years.

Joao Lourenco, who has pledged to boost growth and fight corruption, would inherit an economy mired in recession as gaping inequality, soaring inflation and high unemployment squeeze poor Angolans who have benefited little from a decades-long oil boom.

The People’s Movement for the Liberation of Angola (MPLA) is expected to remain in power but with a reduced majority. 

Its support has waned due to widespread political cronyism, though many Angolans remain loyal to the party that ended 27 years of civil war in 2002.

Voters were seen waiting in orderly queues on a cloudy morning in the capital Luanda when polling stations opened at 7 a.m. (0600 GMT) as police and military manned street corners.

Questions have been raised as to how much power Lourenco will have if he wins, given veteran leader Jose Eduardo dos Santos, 74, will continue as head of the MPLA and have potentially a sweeping say over decision-making.

His daughter, Isabel, heads national oil producer Sonangol and his son José Filomeno is in charge of the state investment fund.

Lourenco on Tuesday dismissed suggestions he would be a puppet president, saying he would focus on leading an "economic miracle", possibly with the help of the International Monetary Fund and World Bank, and prosecute corrupt politicians.

Dos Santos, Africa's longest-ruling president behind Equatorial Guinea's Teodoro Obiang Nguema, will step down after guiding the OPEC-member from Marxism to capitalism while embracing Chinese oil-for-infrastructure investment.

The MPLA's main opponent will be its former civil war foe, the National Union for the Total Independence of Angola (UNITA), while young voters have been lured by CASA-CE, which was formed in 2012 on a promise to disrupt 50 years of two-party politics.

There are concerns about how fair the vote will be after the government cracked down on recently planned public demonstrations. UNITA has said it will lead protests if it believes the MPLA has manipulated results.

An unofficial result is expected by Friday.

But there may be no formal announcement for two weeks as ballot boxes wend their way along pot-holed roads and dirt tracks in a country of 28 million spread across an area twice the size of France.