Charlotte Leslie is the Conservative candidate for Bristol North-West.

Institutions have insatiable appetites. They gobble up the independent-minded, the clear-visioned, the well-intentioned, and incorporate them into their colossus of body – a terrifying prospect.

I write this in the last few hours of being an MP in the 2010-15 Parliament. By the time you read it, I will once more be a candidate, fighting for my mandate to return into that extraordinary institution of the Commons, to serve the people outside it.

This time five years ago, I was fighting to become an MP for the first time. It appeared both a glittering grail and an infinite burden to which I was aspiring, and to the then still non-MP me, a prize fraught with dangers.

My biggest fear was that I, too, would be gobbled up and incorporated by the institution, without my realising it. On becoming an MP, I understood how wellfounded those fears were. I saw how easy it was to succumb to the heady anaesthetic of grandeur, the penetrating whispers of superiority haunting the book-lined labyrinths of Parliament, the persistent reassurance of  routine, and how you can be swallowed alive, quite easily – and not feel a thing.

No doubt the institution, over these five years, has slowly begun its digestive process on my extremities, despite the best of my intentions to fight it. (Just how far it has got is for friends, family and constituents to judge!)  But there are a few watershed moments in which you have to make a conscious choice about what kind of person and MP you want to be – whether you serve the public, or the institution.

I got into a bit of trouble from some for my last ConHome post. But it was a decision to commit my loyalty to the public, not to the institution. To those who criticise me for that – be my guest. It was a statement of my allegiance, not to committees, but to the public they are there to serve.

But I never dreamed, when I entered parliament, that my biggest quest of that five years would be to fight for those who have chosen to serve the public, not the institution – namely, whistleblowers. My work on supporting those within the NHS – who often sacrifice their careers to put the interests of the public over those  of the institution, has introduced me to people who have inspired me.

They have two distinctive virtues. First, the perception to cut through normalisation to see what is right and wrong, when others have become so institutionalised that, for them, what’s normal becomes what’s right. Second, the moral courage to stand up and act on that searing perception, even at cost to themselves.

As I look forward to the coming election, and the public’s disdain for the political establishment, whistleblowers perhaps embody what is missing from politics: an ethos built up by individuals who, whilst having a healthy sense of team-loyalty, maintain focus on what really matters: serving – not pleasing, not wooing – the public, even at cost to themselves.

This is not to say that such individuals do not exist in Parliament. They do, more prolifically than many imagine. But for politics as a whole, the institution, and institutional priorities, seem to rule.

This is not new. One has to wonder what we would know about historic child abuse in our political system if a few more people had then had more respect for duty to the public than for the rules of the club, committee or institution.  But in an age in which there is no longer a wall of deference to hide behind, politics is now more exposed as being institutionally motivated, instead of motivated by the public outside its walls.

As we go into this election, I believe the political dividing line will be drawn between those politicians who are there to serve the public, and those serving their party-political institution, regardless of the cost to the nation. So as the central Labour Party’s desperate attempts to hijack the NHS as a political weapon veer out of control, I have a simple plea to make to aspiring Labour MPs – particularly new ones.

The way your party is using the NHS is not in the best interests of the nation. Deep down, you probably know it. Both our parties have made mistakes, and we each harbour anger about what the other has done with the NHS in the past.

But if you care at all about preserving the NHS free at need for when tomorrow’s children are old, please think again about whether you serve your institution – or the public. There will come a day when you will have to say to your grandchildren whether you were one of the politicians serving the people – who helped build bridges, and came to the table to work across-party to help preserve an NHS free-at-need, or whether you put your own career first and used it simply as a political tool.  I aspire to be the former, and if we are elected, I want to be there alongside you.

Teetering on the edge of re-election (or not) after five years of Parliament leaves me with this thought: careers come and go – especially in politics. But your own moral integrity is with you for life. I’ve made my share of mistakes – all of us have – but if you don’t forcibly remind yourself whom you serve, every day of your working life, at the end of your career you risk looking back and realising that the institution ate you and your integrity up, long ago, and excreted out the remnants. Yes, sometimes standing up against the institution will land you in trouble – but look at the alternative, and I reckon it’s worth it.