In the United States, there was a sixteen-year hiatus between the country's first televised Presidential debate in 1960 and the second in 1976. There were, of course, three elections in the intervening period.
The idea that a similar stalling could befall the UK's embryonic leadership debates seemed unthinkable after the perceived success of the inaugural event in 2010. Millions tuned in to watch three debates involving the main party leaders and the programmes appeared to set the pre-election agenda in exactly the way in which they were intended.
Yet their success in terms of audience share or even advancement of the public interest was never going to be the qualifying criteria which determined whether they would be repeated in 2015. Party political self-interest - which had prevented decades' worth of attempts to make the debates happen - would continue to trump all else.
The narrow considerations of individual parties are complicated further by the vexed question of which leaders should be invited to take part. In a post-coalition, post-referendum and post-UKIP scenario, that is a much tougher poser than in 2010.
Set against this political landscape, broadcasters have today put their pitch to the parties about the form of any debates in 2015 - and given a complicated backdrop, the broadcasters have come up with a complicated solution. Gone are the three, three-way programmes to be replaced with a four-way debate which includes UKIP's Nigel Farage, a three-party event à la 2010 and a two-header involving only the Tories and Labour.
It's an interesting proposition and one which just might give each party enough of an incentive to participate. Is it fair? Perhaps it would be more relevant to ask - could it ever be?
There is no appearance for the Greens, in spite of their having had an elected MP throughout this parliament, compared to UKIP's more recent election-following-defection. UKIP did win this year's European elections, but then the Greens can argue that they have recently enjoyed a similar poll rating to the Lib Dems. Meanwhile, the nationalists will have to make do with their space on the platform of any debates held in their own nations, having once again been denied a UK-wide outing. The common-sense need for devolved issues (no matter how numerous these may be) to be debated within the nations concerned seems justifiable, but the Greens' absence less so.
Of course a line has to be drawn somewhere - with an eye to practicality as much as fairness. It's also worth noting that the ultimate arbiter of what constiutes a 'major party' is OFCOM and they will almost certainly be drawn into the argument.
Unbound by such concerns will be the organisers of a proposed on-line debate, hosted by The Guardian on YouTube. The target audience of 18-40-year-olds is purportedly more likely to engage with such a forum than a linear TV broadcast - somewhat ignoring the fact that linear TV broadcasts are themselves widely available in the on-line world. Moreover, the rationale overlooks evidence given to a parliamentary select committee into the issue - namely, that on-line activity still fails to achieve the cut-through of mainstream media. The benefit of the broadcast debates last time round was the very fact that it caught the attention of a mass audience - the interested, the uninterested and the disinterested.
As for the rules of engagement, it is far from certain that these will remain the same as in 2010 - the Scottish referendum debates have almost certainly seen to that. Whilst the original leadership debates allowed the "contesting" of each participant's arguments following an audience question, free-flowing debate was understandably restricted by strict criteria governing balance. However, the cross-examination section of the referendum debates was not necessarily any more illuminating, with one moderator judged to have lost control on occasion.
Negotiating a middle way - determining who speaks when and, for that matter, who speaks at all - is no small challenge. But the fact that these debates have happened once surely means they must happen again. Would it really be in anybody's interests (the public or the party political) for them to be sacrificed in an interminable balancing act over balance?
