Eastern Cape Premier Oscar Mabuyane has until the end of Friday to respond to a letter requesting a commission of inquiry into alleged "state capture" in the Nelson Mandela Bay metro.

The letter was drafted by the Democratic Alliance's (DA's) spokesperson on cooperative governance and traditional affairs, Dr Vicky Knoetze, and sent to Mabuyane earlier this week.

The party is requesting the establishment of a provincial commission of inquiry because of alleged "systemic corruption and political interference" within the municipality.

This has allegedly led to the municipality being "too crippled" to perform basic functions.

The letter claimed there had been interference by politicians in the procurement of service providers and the appointment of municipal officials.

Other claims include alleged interference by politicians in disciplinary related matters, the "capturing" of the Mandela Bay Development Agency and failure or little progress in dealing with irregular expenditure amounting to R20-billion.

According to Knoetze's letter, the metro's electricity and energy as well as its human settlements directorates were corrupt and EPWP funding was allegedly abused by political appointees.

DA leader in the Eastern Cape Andrew Whitfield said in terms of the Constitution, the premier of a province was responsible for appointing commissions of inquiry.

He added the Provincial Commissions Act made provision for conferring certain powers on commissions appointed by the premier for the purpose of investigating matters of public concern.

"The Provincial Commissions Amendment Bill also states that the premier may proclaim in the provincial gazette the appointment of a commission of inquiry and define the matter to be investigated by the commission and its other terms of reference," Whitfield said.

Mabuyane was given until Friday to respond.

Mayor Gary van Niekerk said he welcomed an investigation into the allegations lodged against the municipality.

He added it must also include the "political interference and mismanagement" by previous governments in the metro.

"We welcome all investigations, especially the R20-billion unauthorised, irregular, fruitless and wasteful expenditure accumulated over a number of financial years and the failure by previous administrations to address this.

"Nelson Mandela Bay Municipality residents deserve full disclosure," Van Niekerk added.

When approached for comment, Mabuyane's spokesperson, Yanga Funani, said the premier had received the letter.

However, he added it was received after it was leaked to the media.

"The premier will apply his mind to the letter and respond at an appropriate time," Funani said.