Foreign observers have reported in a preliminary assessment of Malawi’s presidential, parliamentary and local elections that there have been irregularities, including the absence of a level playing field.

An assessment of preliminary results on Thursday indicates that incumbent leader Peter Mutharika has a small lead over challenger Lazarus Chakwera with about a quarter of votes still waiting to be tallied, the Observer reported.

The European Union (EU) observer mission said the Malawi Electoral Commission organised the elections well, but the pre-election period was marked with tension.

"What we see as a problem," said Miroslav Poche, the EU mission's chief observer, "is the abuse of state resources and also bias by state media." The continental body also criticised attacks on opposition politicians.

Former South African President Thabo Mbeki, who is leading the Commonwealth observer team, said that although elections were well managed it would be premature to declare them free and fair.

"We are not making any judgments — that's a matter that will arise later," said Mbeki.

"When everything has been done, then it will become possible for the observer team to say, 'Now, given everything we have heard and seen, it is possible to say these elections were fair,' and whatever."

But opposition politicians claim they have lost confidence in the vote-counting process underway at the main tally center in Blantyre.

The secretary-general of the main opposition Malawi Congress Party, Eisenhower Mkaka, said the party would not accept the results if their candidate Chakwera lost.

"We have got a state-of-the-art tally centre which is actually collecting results from across the country and from what we have collected, we are quite comfortable that as the Malawi Congress Party, we are winning and therefore any results that go against what we have will not be accepted,” said Maka.

By late Thursday Chakwera was about 5 percentage points ahead of Mutharika. However, the final results will only be announced on Wednesday.