When did this switch from an election scripted by Charles Saatchi to one painted by Salvador Dali? If I had told you a month ago that Gordon Brown would be despatching naval warships to Spain, David Cameron would be jostling with a man dressed as a chicken and down to 30 per cent, and Nick Clegg would be identified alternately as "the most popular leader since Churchill" and a Nazi, you would have called for Nurse Ratched.

But something stranger still is happening in The Election That Flew Over the Cuckoo's Nest. Every day in this country, two big forces artificially drag the British government way to the right of the British people, making it enact policies that benefit a small, rich elite at the expense of the rest. We are not supposed to notice this, never mind try to change it. Yet suddenly, in this election, those forces have been exposed.

To understand what these forces are, you have to start with a fact that is usually kept obscure: Britain is a country with a large liberal-left majority. Eighty-five per cent of us say the gap between rich and poor should be "much smaller", and a majority would get there by introducing a maximum wage that caps the incomes of the rich at £135,000 a year.

Fifty-eight per cent support a dramatic increase in the minimum wage. Fifty-eight per cent want to ditch Trident – an act of unilateral nuclear disarmament. Seventy-seven per cent want to bring the troops home from Afghanistan now, or within a year at the latest. Fifty-three per cent say people come out of prison worse than they go in, and would rather spend money on more youth clubs than on more prison places.

Across most policies, our views are to the left of all three parties. (These statistics are all from Mori, Ipsos or YouGov polls.) And Brits hold these views even though they are constantly told by the media that they are marginal, impossible, or mad.

Ah, you may say, but that's just what people tell pollsters. They vote for the polar opposite: look at Thatcher's victories. But look again. At every election where Margaret Thatcher stood, 56 per cent of the British people voted against her, for parties committed to higher taxes, higher public spending, and lower inequality. The media declared this to be a "landslide" endorsement of her programme of deregulation that continued for decades, and has now crashed the global economy.

Yet in this election, one of those distorting forces – the media – has been bypassed for an electrifying moment, and the second force, our dusty 19th-century voting system, may break entirely on election day.

The British media is overwhelmingly owned by right-wing billionaires who order their newspapers to build up the politicians who serve their interests, and marginalise or rubbish the politicians who serve the public interest. David Yelland, the former editor of The Sun, bravely confessed this week that as soon as he took his post, he was told the Lib Dems had to be "the invisible party, purposely edged off the paper's pages and ignored". Only a tiny spectrum of opinion was permitted. Everyone to the left of Tony Blair (not hard) had to be rubbished – even when their policies spoke for a majority of British people.

Both TV debates, then, have been a very rare moment in which a slightly more liberal-left voice could speak to the public without the distorting frame of pre-emptive abuse and smears. When, for example, have you ever heard the EU defended as plainly and clearly? The window of permissible opinion was opened a little – and people responded with a wave of enthusiasm. It could've been opened wider still – to the Greens, say – and found a receptive audience too.

The reaction of the right-wing press to briefly losing the ability to frame how politicians address the public has been a frenzied panic worthy of Basil Fawlty. They have "revealed" Clegg is a paedophile-cuddling, Gaddafi-licking foreigner and crook who wishes we had lost the Second World War. But now – for a change – people can test the smears against what they see and hear with their own eyes, unmediated, on TV.

Rattled, the right-wing press now demands Cameron start publicly thumping the table and articulating the agenda he whispers to them behind closed doors, and can be uncovered in his policy documents: big cuts in public spending, big tax cuts for the rich. But Cameron sees the polling and the focus groups, and he knows the public loathe his real agenda. That's why his performances in this campaign are so stilted. Once Cameron is forced to address us directly, without being bigged-up by the Murdochracy he has promised to feed and fatten, he withers under the weight of his own deception.

For two 90 minute blocks, the media demonisation of the liberal-left was switched off in favour of equal time and open access – and it revolutionised our politics. If this happened day in, day out, how would our national conversation change?

The second force that badly skews Britain to the right is – I'm sorry – a coma-inducingly dull subject. Even as I mention it, I have to start guzzling Red Bull – but we are now seeing plainly why it matters. At the moment, we have a 19th-century voting system system called First Past the Post (FPTP) which tosses out perverse results – and might be about to produce the most perverse of all.

It is based on a crude principle. An MP is elected if he has more votes than his nearest competitor in his constituency – even if he has nothing like a majority. In many places, they get only 20 per cent of the vote, and still win. These weird distortions only get worse as you get to the national level. Nobody ever adds up the votes at the centre and makes sure the seats in parliament resemble the votes we cast: in 2005, Labour got 100 per cent of power with only 35 per cent of the vote.

But most of the time, this disproportionately benefits the right. Why? Because the British right is unified behind the Tories, while the people who prefer a more social democratic Britain are split between Labour and the Liberal Democrats.

Under proportional representation, this isn't a problem: the split left would come together and form a coalition – and the Lib Dems would be able to block Labour's worst policies, like Iraq. But under FPTP, the divided liberal majority more often loses and has to watch a right-wing minority rule. That's why the Tories in the twentieth century repeatedly got power despite being opposed by a majority.

This system is about to snap. Now the vote is pretty evenly split between three parties, FPTP can't function: nobody knows what freaky result it will throw out. Maybe Cameron will be rejected by 65 per cent of us, but still get 100 per cent of the power at the end of it. Maybe Brown will come third in the popular vote, but still be the largest party in parliament. Maybe Clegg will come first in the vote, but get barely a third of the Tories' seats. Shouldn't this be the last election fought under rules designed for Lord Salisbury's day?

In Britain today, the liberal-left are not just a silent majority: they are a silenced majority. But in this election campaign, the forces shutting them out and breaking them up have been exposed, for a flickering moment. Do we want to go back?

j.hari@independent.co.uk