Over four million people watched the final TV debate of a knife-edge election campaign in Britain on Thursday night, but many voters wondered why Prime Minister David Cameron didn’t take part, something his ministers struggled to explain.

Cameron stayed away, having elected to appear in only one previous leaders’ debate, a tactic his advisers felt would deprive Opposition Labour leader Ed Miliband of the chance to boost his poor personal ratings by clashing with the incumbent.

With just three weeks before what is shaping up to be the closest British general election since the 1970s, Cameron’s Conservatives remain neck-and-neck with Labour in most opinion polls and there is no sign of either coming up with a game-changer before May 7.

Data showed that the second most searched-for question on Google during the 90-minute debate was: “Why is David Cameron not at the debate?”

The most popular question was “What is austerity?”

Miliband urges Cameron again to confront him face-to-face on TV

Even though Cameron was absent, his ministers turned up for the post-debate “spin room” event in London and tried to convince the public, via broadcasters, why the debate was actually a victory for him.

“Do you think we saw the real David Cameron tonight?” one reporter sarcastically asked Liz Truss, Cameron’s Environment Minister, underlining the difficulty of that task.

“I think we saw the reality of what a chaotic coalition would look like,” an irritated-looking Truss replied. “Do you think his personality came through?” the reporter persisted.

Nick Clegg, the leader of Cameron’s junior coalition partner, the Liberal Democrats, didn’t participate either. That opened the door to a five-way debate including Miliband, the leaders of the Scottish and Welsh nationalists, the Greens, and the anti-EU UK Independence Party. For Miliband, it was a prime-time opportunity to showcase his leadership credentials, which are frequently called into question by Britain’s mostly right-leaning press.

Britain’s Opposition Labour Party leader Ed Miliband participating in the televised leaders’ debate in London, late on Thursday. Photo: Reuters

Cameron’s gamble was that the inevitable accusations of political cowardice were a price worth paying. Yesterday, he suggested the event was useful because it gave voters the chance to see how unruly life would be if Labour came to power in a coalition or minority government with the pro-independence Scottish National Party (SNP).

Miliband has ruled out a formal pact with the SNP, but not a looser deal. One snap poll conducted after the debate handed victory to Miliband, though critics suggested the sample of respondents had been dominated by Labour supporters.

Miliband yesterday urged Cameron again to confront him face-to-face on TV: “If he had guts he’d come out and he’d accept my challenge to debate me one-on-one.”

Cameron ruled that out. Seeking re-election for another five years, there was some consolation for the absent incumbent. So far, nothing that has been said or done by any politician has shifted the polls, and viewing figures showed more Britons watched a popular soap opera called Emmerdale than the debate.