IT was actually Gordon Brown who coined the phrase “I agree with Nick”.

He unwittingly came out with it 15 minutes into the UK’s first-ever televised leaders’ election debate in 2010, commenting on the Tories’ unrealistic immigration targets.

By the end of the debate, realisation was dawning that agreeable, insignificant Nick had whipped his ass.

The predicted LibDem seat surge never happened in that election, in spite of Nick Clegg’s deft performance, but then, as now, the fear that it might is always there for the two bigger parties.

They like the status quo. The woefully unrepresentative British electoral system has allowed them to play ping-pong with power for 75 years.

The last thing they want is smaller parties muscling in, especially when one of them might shine. Put two clear-eyed Scottish women in a TV studio with them, armed with all the best arguments on Brexit, and people might think they actually had a choice in this election.

Jeremy Corbyn and Boris Johnson would like nothing more than for broadcasters to push aside everyone else, so how delighted they must be that the broadcasters are obliging them.

Both ITV and the BBC are to hold head-to-head debates between the Tory and Labour leaders, excluding the other parties, and are now, quite predictably and quite rightly, facing legal action from the LibDems and SNP for doing so.

These debates will unfairly skew people’s perceptions of the election contest. Much as we might all enjoy the prospect of Mr Corbyn and Mr Johnson having to explain themselves to each other, it quite wrongly creates an impression that UK politics, like American politics, is a two-horse race and can never be otherwise. We aren’t, and it can. A parliamentary democracy, even one with as skewed a voting system as ours, expresses a plurality of views and it is not the job of broadcasters to exclude important views and parties that might ultimately hold the balance of power.

Ofcom guidance allows for broadcasters to achieve “due impartiality” over the course of several “clearly linked” programmes, allowing ITV and the BBC to meet their obligations by having multi-party debates on other dates (which both are planning to do).

But even so, scheduling two-man debates sends a blunt message to voters that is damaging to every other party. It says: only the big two really matter.

What’s the bet that when it comes to debating with the panoply of party leaders, Mr Corbyn and Mr Johnson will discover more pressing commitments and send proxies, or no one at all, in order to belittle their opponents further? Both Mr Corbyn and Theresa May shunned a multi-party debate in 2017. It’s all about shoring up their undemocratic duopoly.

This is a unique, and uniquely important, election. It’s the Brexit election, happening because of Brexit and in order to settle Brexit.

Ofcom’s Broadcasting Code states that “broadcasters must take into account evidence of past electoral support and/or current support” and that they must consider giving “appropriate coverage” to parties and candidates with “significant views and perspectives”.

The code gives huge latitude to broadcasters, but even so, in the spirit of the code, both Jo Swinson and Nicola Sturgeon should be included. What is being unwaveringly pro-Remain and in favour of a second referendum on Brexit, if not a “significant perspective”?

Polling shows that more than half of voters back Remain. In a head-to-head debate between Labour and the Tories, those voters will not hear their views championed. They will listen to Mr Corbyn, who favours Brexit in his heart, and will howl in frustration as he fails to take the opportunity to make the (overwhelmingly positive) case for staying in the European Union, while Mr Johnson gleefully misrepresents the supposed advantages of leaving. How by any reasonable definition does that reflect the range of views in the country on such a critical issue?

As for electoral showing, the Liberal Democrats only polled 7.4 per cent of the vote in 2017. On that basis, Ms Swinson has a tenuous claim to inclusion. But the LibDems are at 16 per cent in the polls now and beat their larger rivals at the European elections in May, as well as seeing their vote share surge in the English local elections while the big two saw theirs sink. The SNP holds the third-largest share of seats in the House of Commons and dominates politics in Scotland. Guidance on Ofcom’s code says that debates can focus on parties that have “a realistic prospect” of forming the UK Government (which would tend to exclude the SNP), but the code is out of date. It does not recognise that increasingly in our fractured politics, third and fourth parties are crucial because the big two are finding it harder to get outright majorities. A third party could find itself in government as a coalition partner or exerting huge influence on government. Either the LibDems or the SNP could hold the balance of power in a few weeks’ time. In 2010, thanks to the leaders’ debates in which Nick Clegg participated, voters knew who they were getting as deputy PM; will they this time around?

There is nothing wrong with wanting a debate format that engages people. We are a society hooked on emotional gratification. We love the sentimental highs of X Factor or Strictly, we’re carried along in outrage and joy by our TV dramas. But do we need a villain and a hero in our politics too, as some TV managers seem to assume?

One former BBC executive has argued that multi-party debates are “frustrating” for viewers. Well, democracy is frustrating. How annoying of British voters not to file dutifully through the dual political silos designed for them 70 years ago. How irritating of them to want representation by people who actually share their views. But what’s more important: reflecting the range of views that exist in the country, or skewing reality for the sake of a simplistic format?

Sky News has invited the LibDem leader to participate in a three-way contest, but ITV and the BBC are sticking to their guns, for now. They are set on airing debates that exclude the viewpoints of more than a third of voters. Maybe the courts will help them change their minds.

Read more: SNP take legal action against ITV over exclusion from election debate