A man who stabbed his wife to death on the forecourt of a Wellington service station because she was unfaithful to him is due to be sentenced at the High Court in Wellington this morning.

Emani Tinoa'i, 49, was found guilty last month of murdering Moliga Tinoa'i, 42, on the forecourt of the Johnsonville Mobil station on March 14, last year.

During the trial, the defence said the Wellington butcher "lost his mind" and stabbed his wife to death in a "frenzied explosion of passion".

The court was told Tinoa'i was provoked by long-standing problems within his marriage, including his wife's infidelity.

However, the crown argued Tinoa'i had a history of violence towards his wife and repeatedly threatened to kill her.

"This killing was not a case of loss of self control, this was the final expression of Mr Tinoa'i's attempts to control his wife," Crown prosecutor Grant Burston said.

"He threatened to kill her and he did."