The latest issue to excite commentators in Westminster has been the ongoing row over the General Election debates. David Cameron’s refusal to participate in the broadcasters’ proposed format has led to accusations that he is ‘frit’ and a rare show of unity from Labour, the Liberal Democrats and UKIP in condemning the Prime Minister.

There has been much speculation over the reasons for Cameron’s refusal. The Conservatives are perhaps playing a disingenuous game by posing as the champions of the Greens in this affair. As many commentators have pointed out, fear of the positive effect that a debate could give his rivals is a much more likely motive for Cameron’s decision. In particular, Cameron and the Conservatives should be afraid of the boost that the proposed four-way debate could give to Nigel Farage and UKIP.

The debates of 2010, and the ensuing boost in popularity for Nick Clegg, showed the advantage that can be gained from taking an anti-Westminster line attacking the political mainstream. In a four-way debate without the presence of another minor party, such as the Greens, this role would inevitably be taken by Farage. Farage is an effective performer in debates and has his anti-mainstream pitch well-honed now. He demonstrated how effective this can be in last year’s European election TV debates, where he comfortably bested Nick Clegg and gained valuable publicity for his anti-Westminster messaging.

It is true that the effect of TV debates can be overestimated. Despite Nick Clegg’s huge boost in popularity in 2010 from the debates, this did not translate into an electoral boost and the Liberal Democrats actually performed worse than in 2005, going from 62 seats to their current 57.  The UK does not have a strong tradition of TV debates, so it is hard to quantify how influential they are likely to be. Even in America, where there is a much stronger tradition and they are a key part of presidential campaigns, research conducted by Gallup have suggested they rarely have a significant impact on voting intentions.

However, 2015 is set to be the tightest election race in over 30 years and the Conservatives will be rightly wary of presenting any opportunities to their rivals to gain extra traction with voters. In particular, in such a tight contest one of the key advantages that Cameron has over Ed Miliband is his consistently higher personal approval ratings. The choice over who they want to be their next Prime Minister could be a vital factor in swaying undecided voters in tight marginal races, and it is understandable that Cameron would do everything he can to protect his advantage here. While Labour and others will now seek to make political capital out of Cameron’s refusal, it is unlikely that this will hurt him as much as a poor debate performance would. This is the gamble that the Conservatives appear to be making. Time will tell if it is the correct decision.