"The Constitutional Court found in favour of nine political bodies, of which five political parties and four coalitions," the Court said in a statement.

The body, which has to okay parties ahead of the polls, considered applications of 27 political bodies, but rejected 18.

The Popular Movement for the Liberation of Angola (MPLA) and main opposition National Union for the Independence of Angola (Unita), as well as three other parties, were cleared to take part.

These were the National Liberation Front of Angola (FNLA), the Party for Social Renovation (PRS) and the New Democracy (ND) party.

Brand new opposition coalition Broad Convergence of Angolan Salvation (Casa), which was founded last March by a former Unita leader, is one of the four that will run for election.

Parties who were excluded have 48 hours to appeal. Some already indicated their opposition.

"The eviction of these parties, very critical against the powers that be, shows that the court isn't an organ of justice but an armed wing of the MPLA against the opposition," said Sediangani Mbimbi, president of the Democratic Party for the Progress of the National Alliance of Angola (PDP ANA), which didn't make the cut.

"We can appeal but in front of the same court we have little chance to achieve our cause," he said.

Opposition parties have decried what they called widespread fraud in the registration process.

The ruling MPLA won the last vote in 2008 with over 81 percent.

Angolan President Jose Eduardo dos Santos and the former boss of the powerful state oil company Sonangol were last month named to the top of the ruling party's list for the August 31 vote.

Under a new constitution ratified in 2010, the president will be chosen from the top of the winning party's list.

The polls are almost certain to re-elect Dos Santos, whose 33 years in power make him Africa's second-longest ruling leader after Equatorial Guinea's President Teodoro Obiang Nguema.