Libya's interim parliament has confirmed the appointment of Ahmed Maitig as the new prime minister.

However acting Congress chairman Ezzedine Al-Amawi later declared the ballot illegal after a row over the procedure.

On Monday, a decree signed by the head of Congress, Nuri Abu Sahmein - who was absent on Sunday - named Mr Maitig as interim prime minister.

Mr Maitig, 42, is the country's fifth PM to be appointed in the past two and a half years.

Mr Maitig, from Misrata, will have two weeks to propose a cabinet, which will need to be approved by the Congress.

This may prove to be a difficult task following the controversy over his appointment, says a source.

Some deputies had claimed the vote on Sunday was illegal, arguing that it continued after Mr Amawi had declared the session over. Other members argued that no laws were violated.

Mr Amawi said it was unconstitutional and ordered Libya's caretaker PM, Mr Thinni, to remain in power.

But the new appointment was ratified on Monday in a decree signed by Mr Sahmein on his return to parliament.

Mr Maitig had clinched 121 votes in the 185-seat chamber - just exceeding the 120 required, the ruling said.

Elections for a new parliament that will replace the General National Congress are expected later this year, and a new cabinet is expected to be formed.