Clueless President Emmerson Mnangagwa has no choice but to engage rival Nelson Chamisa if Zimbabwe is to be rescued from its present political and socio-economic mire, a senior opposition official has said.

"The way forward is that Emmerson has to talk to Chamisa," said former finance minister Tendai Biti in an interview straight after being sworn-in as MP for Harare East on Wednesday.

"Chamisa holds the key to this country. Emmerson has to have wisdom; the gods must pray that Emmerson has wisdom in his head."

President Mnangagwa narrowly avoided a run-off ballot in the July 30 elections and had to wait for the Constitutional Court to rule on a challenge by Chamisa before he could be sworn into office.

Despite the challenge being dismissed by the apex court, the opposition still maintains that Chamisa won the vote, and accuse electoral authorities of rigging the count in Mnangagwa's favour.

Biti, a principal in the opposition MDC Alliance which Chamisa heads, said Mnangagwa lacks the ideas to turn Zimbabwe's battered economy around.

He said the spike in prices of basic commodities after the hotly disputed election was a sign that the country was headed for even more choppy waters.