You may have seen it on The Huffington Post. The Labour Party is looking for an Executive Director, Rebuttal and Policy.

The job description is written in jargon, but at the bottom of page one, provided you're still awake, it says: "Lead and manage the Labour Party's...rebuttal and attack, including at PMQs", which returned yesterday.

Thus Ed Miliband is after a new joke-writer. Dare it be suggested that the previous one wasn't very good? There were Prime Minister's Questions last year during which David Cameron's taunting of his shadow became almost cruel, when the target had become far too big. It was the last session of 2011 when Cameron said of Nick Clegg, "It's not like we're brothers or anything."

So Ed needs better material. But his performance needs to rise a few notches too. As Frank Carson famously remarked, "It's the way I tell 'em!" Stand-up, or any kind of public speaking, is only partly about the writing. You have to warm to a comic to find him funny. Eddie Izzard leaves me stony-faced. He could relate the funniest, most cutting-edge observations in the world, and I would still consider him dull. If Billy Connolly, on the other hand, told a series of 'knock-knock' jokes, I would fall about laughing.

It's the same with politicians. Tony Blair, with his thespian skills, could take a third-rate speech and get a standing ovation. In contrast, Gordon Brown might orate something written for him by Ian McEwan or Julian Barnes and have the audience scurrying for the exit. Ed Miliband, with his geeky appearance and nasal voice, is never going to be a political Olivier.

As well as deciding whether we like a politician, we also make a judgement about what sort of a person they are. This is, perhaps quite often, rather unfair. After all, you need to meet someone to get to know them, to make a proper judgment. Very few of the voters will ever get to shake Ed Miliband's hand, and so he has to rely on the image he projects in the media. And that image took a bit of a nosedive last week.

It was a cliché; something more closely associated with the army than with politics. One can imagine a sergeant major giving an errant private a 'severe dressing down,' but would Ed Miliband do such a thing? Could he? Or would he profess exasperation instead? And then give lines and detention? All with rather a heavy heart, as if it was hurting him as much as it was the recipient.

Whoever came up with the phrase, it was an unimaginative response to Diane Abbott's tweet about white people loving to divide and rule. A friend posted on Facebook: "Labour sources say Diane Abbott has been given a 'severe dressing down' by Ed Miliband. Terrifying." One of the responses read: "She would batter him in a fight." To which the initial poster replied: "I think anyone would." It reminded me of the time when Denis Healey said that facing Geoffrey Howe across the dispatch box was "like being savaged by a dead sheep."

But Healey was wrong about Howe. It was Howe who rose up and played a major part in Margaret Thatcher's downfall, telling the Commons in November 1990 that the soon to be former prime minister had, in his opinion, been undermining her Chancellor. During a dramatic resignation statement, he told MPs: "It is rather like sending your opening batsmen to the crease, only for them to find, as the first balls are being bowled, that their bats have been broken before the game by the team captain."

Thus the man so memorably derided by Healey had considerable courage. Ed Miliband, too, showed he had a ruthless streak by entering a leadership election also containing his older, more experienced brother. His victory perhaps proved he'd been right to go for it.

But the ability to beat another individual does not necessarily suggest leadership potential. It seems unlikely that the softly-spoken Howe would ever have led his party. Gordon Brown, after a long campaign of attrition, eventually succeeded in removing Tony Blair from Number 10, but proved inept as his successor. And Ed beat David, but can't even persuade his own gurus he's doing a good job - Lord Glasman writing last week that the Labour leadership appeared to have "no strategy, no narrative and little energy", also commenting that Ed needed to change his approach if he was to "break through."

'Breaking through' is about perception. My (female) friend's assertion on Facebook that a severe dressing down from Ed Miliband was a risible idea was about perception too. No-one wants Ed M to be a bully, in the alleged style of his former mentor, Gordon Brown, but a leader must have authority. Perhaps he should have sacked Diane Abbott - it would have been actions, not words.

He tried to plough a new furrow earlier this week. In a speech to London Citizens he made lots of encouraging noises, admitting his party will have to adapt to lean economic times, saying that "Labour can deliver fairness when there is less money around." He also announced "three new ways of delivering fairness" in a period of austerity, including "making choices that favour the hard working majority."

His new Executive Director, Rebuttal and Policy, will of course be doing far more than thinking up a few jokes for PMQs. Lots of substance will be required, and in that regard, there's plenty to work with. In addition to a flat-lining economy, the coalition is making major changes to health, benefits, and education. Whether such reforms are right or wrong, well-thought-out or drafted on the back of a fag packet, they need to be challenged and scrutinised.

Margaret Thatcher was aided by two Labour leaders who never appeared likely to become prime minister: Michael Foot and Neil Kinnock. Tony Blair was assisted in the same way by William Hague, Iain Duncan Smith and Michael Howard.

Thus the last few decades have been marked by several arguably weak opposition leaders. A stronger alternative now, at such a difficult economic juncture, would benefit Britain.

By the way, that job description also mentions "horizon scanning". Is that to watch out for attacks against the Labour Party, or against its leader?