LISBON, Aug 30 (Reuters) – Angola’s main opposition party has submitted a legal complaint challenging the electoral commission’s finding that the governing party won last week’s election, a letter seen by Reuters shows.

In a separate statement on Tuesday, the opposition party, the National Union for the Total Independence of Angola (UNITA), said it would file a complaint that would have the effect of suspending the declaration of results of the vote.

It was not immediately clear whether UNITA’s letter to the commission, sent on Monday, was the same complaint.

After the most closely fought election since independence from Portugal in 1975, the commission reported on Monday that 51.17% of voters had supported the ex-Marxist People’s Movement for the Liberation of Angola (MPLA), prolonging its nearly five decades of uninterrupted rule.

Read more: Angola’s governing party wins divisive election extending long rule

UNITA, its longtime opponent, got 43.95%, its best result ever, according to the commission. Read full story

UNITA’s letter says the party’s representative at the commission “was not granted the right to record in the result sheet his complaint about the electoral results”.

The leader of UNITA, Adalberto Costa Junior, has repeatedly said in the past few days that he does not recognise the results of the vote and that complaints have been filed.

“UNITA reiterates that it will not recognise the results announced by the National Electoral Commission until the complaints already in its possession are resolved,” the party said in its Tuesday statement.

Under Angola’s rules, if UNITA wishes to challenge the results it must first lodge a complaint with the commission. If that is rejected, the party can take the matter to the Constitutional Court, which must rule within 72 hours.

(Reporting by Catarina Demony; Writing by Francesco Guarascio; Editing by Bradley Perrett)