16/06/2015 11:59 BST | Updated 16/06/2016 06:59 BST

We Want This Campaign to Be About the Best Labour Has to Offer - Negative Briefing Has No Place in This Debate

We lost the election. And it hurts. But the worst thing we can do now is to descend into in-fighting, squabbles and rows. We need a debate about the future of the Party and the future of our country. At times that debate will be fierce - it should be. There are big questions about how we put together a plan for economic growth - based around high quality jobs in growing, thriving high tech businesses and advanced manufacturing firms. There are big questions too about how we developed the skilled workforce we need for the future, how we create a childcare system that gives families more choice about how they bring up their children and how we build an NHS that can keep up with growing demand. And we will disagree - it would be odd if we didn't. This is a leadership contest, after all.

But what we mustn't do is get drawn into unpleasant anonymous briefing and counter-briefing either between campaign teams or across the Parliamentary Party. It's macho. It hurts only ourselves and it's what the Tories want us to do. They would love it if Labour went back to a time when factions tore strips off each other in late night bars.

There are some who will say this is just part of politics - it's just playing the game. Well, it isn't and we mustn't allow it to be. Underhand briefing is unhealthy, it backfires and it shrouds the very real debates on substance that need to happen and need to happen on the record.

So, on behalf of Yvette's Leadership Campaign, I am today making these promises:

  1. If anyone is speaking on behalf of the campaign, they will do so explicitly on the record. There will be no unattributed negative briefings about other candidates because that's not the kind of politics Yvette has ever wanted to champion
  2. If anyone else is speaking to you and claiming to do so on Yvette's behalf and wants to criticise opponents - you can take it from me that they do not speak for the campaign or Yvette - and if she or I get to hear about it they will have lost our trust and our respect. I hope that all of the candidates will join me in making that pledge

If Yvette disagrees with things the other candidates are saying she will say so herself - on the record or in interviews.

We want this campaign to be about the best Labour has to offer. Negative briefing has no place in this debate.

Shabana Mahmood is the Labour MP for Birmingham Ladywood and Shadow Chief Secretary to the Treasury