One of the greatest temptations of radical opponents of the status quo – myself included – is to indulge the endemic cynicism that exists towards politicians. “They’re all the same”, “they’re all in it for themselves”, “they’re just lining their own nests”, “they’re just interested in power” – these phrases will be familiar to anyone who gauges popular opinion of our political elite.

So it was with some sympathy that I read comments by Ed Miliband – he who despicably cannot eat a bacon sarnie – to the press pack last night. Make this election about “issues, choices and beliefs that matter to the country”, he begged. “One of the biggest enemies of politics is cynicism, the belief that we are all in it for base motives.” And here’s the thing: it is those who believe in radical change who suffer most from this cynicism.

Let me caveat this heavily. One of the reasons people are so cynical about politicians is that Westminster’s denizens have behaved so appallingly. They berated poor people receiving tiny amounts in benefit fraud and then shamelessly milked their expenses. The Blair government spun the country into a catastrophic war in Iraq – the effects of which we still suffer – on a pretext that was false. And then in 2010 the Liberal Democrats inspired young people with the promise of free education; young people marched to polling stations for the first time, full of hope, only to be quite possibly left with a lifetime of bitterness towards politicians.

The worse that politicians behave, the more they undermine people’s whole faith in the democratic system as a potential vehicle of change. The polling speaks for itself. One poll by Ipsos Mori in 2013 suggested that more than half of all Britons believed MPs put their own interests first, and only 8% believed MPs put their constituents first; just a fifth trusted them to tell the truth; and 33% believed all or most used their power for their personal gain. This contempt for politicians is not new – and politicians of course bear much responsibility. But it suits powerful media and corporate interests very well.

Why is it not tempting for the likes of me to indulge such cynicism? We live in a country where unemployed people, immigrants, public sector workers and other people not exactly abounding with power are scapegoated for our society’s many ills. The finger of blame needs to be redirected to the powerful, and that certainly includes politicians. But if we end up thinking that politics is the preserve of the cynical and the venal then nobody will ever believe it is capable of changing anything. Promises – however positive and progressive – will always seem cynical and duplicitous, useful for courting votes but never to be implemented.

Take Miliband, a man pilloried in the most personal way by the media for being, basically, a bit odd. He has made pledges which – in my view – are not radical enough, even if they are facing in the right direction: such as freezing energy bills, increasing the top rate of tax, introducing a mansion tax, repealing the bedroom tax and NHS privatisation, somewhat tackling zero-hour contracts, and so on. According to the polls, people support these policies: hell, they’d like to go further, with the renationalisation of rail and energy, for example, even winning over many or most Tory and Ukip voters. But voters simply do not believe such promises will ever be implemented. Arguably the more radical and popular the promise, the more it feeds into a sense of, “Oh, they’ll promise the earth to get elected.”

I spend a lot of time talking to young people: this week, talking to inspiring students in comprehensive schools in Walthamstow and Surrey. They have hopes, fears, insecurities, dreams. But all too often they do not see politics as a means to address them. The media pillories politicians and politics, not because they’re “sticking it to the man” but because they know democracy is the only potential counterweight to a rapacious elite that rules Britain. And before I’m accused of hypocrisy, I too am among those who have risked fuelling a nihilistic cynicism. Yes I want more politicians who say what they mean and mean what they say. But the contempt towards politics does little for those who want real change and much for those who defend the status quo.