The off-stage winner of Thursday's TV event
On social media there was one clear winner of Thursday's TV event: the audience.
The result of the UK general election is as uncertain as ever, and commentators were divided on which of the three party leaders participating in the television interviews on Thursday night came out on top. But there was rare across-the-board approval of one thing: the tough questioning by a studio audience in Leeds.
"This must be the soundest audience ever assembled by the BBC," tweeted Fraser Nelson of the Spectator magazine. "I love this audience!!! can we get them into all lobby press conferences," said Beth Rigby of the Financial Times.
"Blimey. Wouldn't cross this audience would you? This is how it should be. Make politicians fear the people," commented the Guardian's Owen Jones.
On Twitter, the hashtag #bbcqt was used more than 275,000 times during the programme - making it a top worldwide trend, but with significantly lower numbers than last week's challengers' debate and the earlier seven-party debate.
The leaders themselves acknowledged the difficult questions. David Cameron's thank you tweet to the audience was shared more than 1,000 times, while Nick Clegg wrote: "Very much enjoyed taking part in that special @bbcquestiontime. Great format, great questions, great audience, great show." Labour leader Ed Miliband wrote "Thanks for the questions on #bbcqt. There's a clear choice."
The letter - and a tweet 'campaign'
Cameron was the first to be grilled and he provided the first trending moment of the night when he produced a copy of the letter written in 2010 by Labour former chief secretary to the Treasury Liam Byrne which declared: "There's no money left." Conservative supporters were quick to retweet photos of the letter, which have been a stalwart of their social media campaign over the past few weeks.
All political parties co-ordinate their social media output but Conservative accounts caught flak for sending out particularly repetitive messages. The pattern was spotted by Robert Hutton, a political reporter for Bloomberg (whose boss, the former mayor of New York City, has just given Cameron one of his rare endorsements). Hutton noticed that a number of Conservative accounts tweeted about Cameron's "strong, commanding performance" in the moments after the Prime Minister left the Question Time stage.
The messages all appeared to be original tweets rather than retweets, which led to the implication that the messages weren't spontaneous thoughts but rather part of a calculated campaign. Hutton's screengrab of the co-ordinated tweets was itself retweeted more than 1,500 times. "When you get caught out at social media..." commented Twitter executive (and Conservative opponent) Gordon MacMillan.
A slight stumble
Evidence suggests that Labour supporters have a loud, well-organised voice on Twitter - witness the recent #Milifandom trend. On Thursday many of the most-retweeted messages came from Labour politicians and backers. However, some Conservative messages did break through. The hashtag #JustNotUpToIt - a criticism of the Labour leader - was used more than 4,500 times while the Labour-driven hashtag #TheChoice was only used 2,000 times.
The Conservatives also had a strong showing on Facebook - a social network where they have an advantage. An hour after the special programme, a video of David Cameron speaking had been viewed more than 50,000 times, while a similar clip on Labour's Facebook page had only reached 10,000 people.
Unfortunately for Miliband, his most noteworthy moment of the evening on social media came when he tripped up as he left the Q-shaped Question Time stage. Video of the stumble quickly appeared on Vine and were viewed hundreds of thousands of times.
Miliband's name continued to trend well after the programme finished as users continued to debate his assertion that his party would not enter a coalition with the Scottish National Party. And his comments that Labour did not "overspend" when they were last in power generated more than 1,500 tweets.
Clegg and university fees
Liberal Democrat leader Nick Clegg's comments about his U-turn on tuition fees were widely discussed on social media. James O'Shaughnessy, a former Conservative policy chief wrote: "Clegg… wasn't between 'rock and hard place'. I was in the room when he decided to vote for it. He was keen" - a tweet that was shared more than 1,500 times.
Clegg's robust response that he had "apologised for tuition fees" but wasn't prepared to apologise for "putting the country first" when entering a coalition received widespread praise from Liberal Democrat supporters. "I'm a student Nick, I actually think you did the right thing with fees. Good luck in Sheffield," tweeted Jimmy Rushmore, a politics student at Exeter University.
Watching from home
The leaders of three other parties - UKIP, the SNP and Plaid Cymru - weren't invited to the Question Time debate but did appear on separate interview programmes later in the evening.
UKIP's Nigel Farage used the off-stage time to lob tweets at the other party leaders: "The career political classes value their commitment to the EU more than British public opinion," one read.
The Scottish National Party - with their organised and influential social media machine - attacked Miliband's economic policies. "Labour want further austerity cuts - #voteSNP to end austerity," said one message. And this anti-Conservative image was shared hundreds of times:
Plaid Cymru also took aim at the biggest parties by tweeting out quotes from their leader's interview: "Ruling out a deal with SNP was irresponsible of Miliband. I thought he wanted to stop the Tories." Meanwhile, Green Party leader Natalie Bennett - who didn't get any air time - tweeted that there was "no real alternative on show".
One of the most unexpected trends of the debate came on Instagram, where a post protesting about the president of Burundi, Pierre Nkurunziza, became more popular than any other photo with the hashtag #bbcqt. Authorities in the central African nation have blocked social media in the wake of protests against Nkurunziza's plan to seek a third term, and protesters apparently added the tag because of its worldwide popularity.
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