I worked on Theresa May’s disastrous election campaign – this is what the Tory candidates need to avoid

After the bitterness of this leadership election, will a government be able to hold itself together, asks Salma Shah

Naturally, every candidate in the field has spoken of their integrity (PA)

A long time ago, in the days of Theresa May’s premiership, I sat in CCHQ for the 2017 election campaign, manning the broadcast desk, essentially acting as a glorified political-guest booker. It was simple enough, Theresa was on course for a barnstorming majority. Every obstacle in her path had been flattened without effort. All she needed to do was remain static. No gains, no losses.

Then, at some point in the middle of that election, despite protestations they hadn’t, everything had changed. It became obvious to anyone with access to the news that things weren’t going well.

The eagerness of the cabinet and junior ministers to fill up the broadcast rounds diminished, as did their enthusiasm for being told off, briefed against and back-bitten. When the result finally came in, the retribution was swift.

No one ever really paid attention to the lame duck PM again after that. Cabinet leaks and angry briefings dogged her administration and the parliamentary operation was never out of crisis mode. Authority, once drained, is never regained. Her Brexit deal was always in sight but never within reach as she left Downing Street defeated.

It should serve as a reminder to candidates in the latest Conservative leadership campaign. In these testing and unpredictable times, most things are outside of your control. Even in victory, you never know when you’ll lose your lead quickly, followed by your dignity. While at the top, behaviour should be consistent with that.

Naturally, every candidate in the field has spoken of their integrity, their goodness, and how we can trust them with our most precious treasure: our vote. But how are they going to prove it? Already, dossiers with smears against others have circulated and mysterious briefings have appeared on Twitter.

A general disrespect for rivals is a sure way to make the next administration as testy and resentful as the last two. On 5 September, someone will have to walk through the black door and form a cabinet, sustain a government for about 18 months, and launch a winning election off the back of it. That can only be achieved through unified focus.

This contest has already laid bare disagreements on tax and spend, and differences of opinions on huge issues like the net zero target. How can a cabinet be formed with everyone at odds, seemingly there only to represent a point of view – a caucus – rather than learn how to compromise to get to a decision?

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Campaigning from within a cabinet defeats the purpose of collective responsibility. The Conservatives had that in the run up to the leadership race, and we’re now seeing everyone pointing fingers at each other, highlighting shortcomings on both fundamental issues but mostly on rubbish.

I discussed this with a veteran of previous campaigns and an old friend. His view was that campaigns get tetchy, even a little violent, but it doesn’t necessarily follow that they’re fatal to the team in the aftermath. I cannot agree.

If the Conservative Party is going to restore order to government, it needs to begin by restoring order to its contest. Right now the race for the premiership is wide open – but after the bitterness will a government be able to hold itself together?