Former minister Stuart Nash will not contest his Napier seat at the election in October and will instead leave Parliament and politics.

Nash was sacked from Cabinet last Tuesday following the revelation he leaked confidential Cabinet information to two donors.

He made the announcement in a Facebook post on Monday afternoon, saying that after speaking with his family he had “decided to stand down from politics at this year’s election”.

“Nearly six years in Cabinet, nine years as the member of Parliament for Napier and 12 years in Parliament since 2008 have provided me with the most amazing opportunities to really make a difference to our country and my electorate of Napier. But it’s now time for someone else with passion and drive to step up,” Nash said.

Nash has already been selected as Labour’s candidate for Napier. He will now need to resign that selection and the party will need to select a new candidate.

He defends a majority of 5856, making the seat somewhat marginal and open to flipping.

The National Party has selected Katie Nimon to run for the seat and thinks it could be flipped. Leader Christopher Luxon has been spending time in the electorate touring the city with Nimon.

In his post, Nash pointed to there being “many many highs - and a couple of obvious lows” to his career.

 “I have made a number of lifelong friends from both sides of the House as well as up and down this wonderful country. I have had the privilege of serving in the Ardern Cabinet during the darkest of days, managing crisis after crisis after crisis, while driving forward an ambitious and progressive agenda of continuous economic and social improvement and transformation. While the work has been very rewarding, and both intellectually and professionally stimulating, it has also been incredibly taxing on relationships with family and friends.

“It’s now time to address this balance,” he said.

• 'Inexcusable': Stuart Nash sacked from Cabinet after new email emerges
• Prime Minister Chris Hipkins to decide Stuart Nash's future after new email emerges
• Jason Walls: There's plenty more to come from Stuart Nash saga
• 'Error of judgement': PM's staff sorry over Nash email; full timeline of saga released

Nash said it had been “an absolute privilege and a pleasure representing the people of the Napier electorate in Parliament these last nine years.

He closed the post with a quote from United States President Theodore Roosevelt:

“It is not the critic who counts: Not the man who points out how the strong man stumbles or where the doer of deeds could have done better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly, who errs and comes up short again and again, because there is no effort without error or shortcoming, but who knows the great enthusiasms, the great devotions, who spends himself in a worthy cause; who, at the best, knows, in the end, the triumph of high achievement, and who, at the worst, if he fails, at least he fails while daring greatly, so that his place shall never be with those cold and timid souls who knew neither victory nor defeat.”

Nash had been dogged by scandal in his last days in Parliament and had been pulled up for multiple violations of the Cabinet manual.

Last week, Prime Minister Chris Hipkins asked the Cabinet Secretary to review communications between Stuart Nash and his donors.