Nothing wrong with Bill English endorsing Wellington mayoral candidate Jo Coughlan - John Key

Wellington mayoral candidate Jo Coughlan (Supplied)
Wellington mayoral candidate Jo Coughlan (Supplied)

Prime Minister John Key has no qualms with his right hand man and Finance Minister Bill English endorsing his sister-in-law Jo Coughlan to be the next Wellington mayor.

Mr English has appeared in online videos and brochures as part of Ms Coughlan's campaign, talking about her leadership and abilities as a team leader.

His brother Conor is married to her.

Mr Key says the public endorsement is fine, and most people would understand.

"I don't think it's nepotism, I think it's a strong belief that he feels she's the best candidate," he says.

"He knows her well. He's bound to have a pretty strong view about whether she's good, bad, or indifferent," the Prime Minister says.

There's no rule that forbids Cabinet ministers from backing candidates in local body elections, and Mr Key says the Cabinet manual outlaws endorsing products, not people.

But while Mr Key is happy for his second-in-command to endorse a candidate, he says he'd never do it himself.

"I have a lot of respect for Jo but there's a lot of different candidates and in the end, I've taken the call as Prime Minister that I'm going to take a neutral view.

"I choose not to as a general rule because I have to work with all the various different mayors and I've just made the call myself that I'm not going to do that," he says.

The Prime Minister doubts Ms Coughlan's ties would affect Mr English's working relationship with the capital's mayor, whoever it is.