16/04/2015 06:12 BST | Updated 15/06/2015 06:59 BST

Green Leader Natalie Bennett Is an Uninspiring, Joyless Communicator

A leader of a small party needs to sell a vision and connect with voters' emotions to gain traction in a general election campaign - and from the evidence so far Green leader Natalie Bennett doesn't have the charisma to do so.

This is a shame for the Greens, because with rising inequality and environmental issues high on the agenda they should be a significant part of the debate. Not least acting as a counterweight to UKIP.

Instead Bennett just doesn't seem to have the personal magnetism necessary for her to cut through and for her party to make the impact it should.

Here are some examples of some poor communication decisions:

She closes her eyes a lot when she speaks. It's a subconscious way of blocking out the world - and not something a party leader who wants to engage with her audience should be doing. It comes across as a little shy and disconnected.

When being interviewed she tends to display a closed and defensive posture. Bennett doesn't smile easily, giving anyone coming across her the impression of being in the presence of someone who's a bit severe (a sense of humour matters hugely in elections). I'm sure that she is not like this in private but you can only judge someone you don't meet personally on what you see, hear and feel.

Her hands tend to focus inwards. She's not very expressive with her gestures. Someone who's really at ease with what they're saying will find their hands compliment and break up their speech, adding a little influence to the message. This doesn't mean being expressive like an Italian - but it does mean more than just holding your hands clasped in the lap.

The way Bennett speaks matters too. Her rhythms are fast and quite edgy, which makes her seem slightly spiky.

And then there's her accent. This shouldn't matter but on some level it will be a factor. Part of the British electorate will be thinking 'why am I voting for an Australian?' If you're English, instinctively (and if you're on the fence) you may gravitate towards the person who sounds a bit like you. It's not a xenophobic thing, it's about comfort. Neil Kinnock and his Welsh accent found this to their cost in 1992.

As an ex-journalist Bennett should be more than aware of how important a strong personality is to getting her message out. Yet she's an uninspiring and overly academic politician who seems a bit joyless. These are cruel words for a person who clearly has compassionate intentions. Sadly, though, meaning well doesn't make for a good leader by itself. Caroline Lucas would have been a stronger choice. After all leaders are the messengers for the party and without a well presented message you won't be able to engage.

There's a great contrast with Nigel Farage here. When you're running a small party with specific issues you want to focus on, the leader should have a huge head of steam behind him or her. They should be rebellious, saying to the mainstream leaders 'bring it on'. The passion of this challenge must come through, yet Bennett just seems defensive. What a contrast with UKIP, whose leader speaks passionately about policies and is articulating those policies in a way lots of voters can relate to.

When all these weaknesses are put together as a package the result is a politician who comes across as "not being ready". It's not necessarily her fault; some people are natural extroverts and some are very experienced in this kind of arena. So what can she do to fix it?

The answer is confidence. My definition of that is: "knowing you can deliver a decent message and being happy to do so". When something is second nature the anxiety about messing up disappears. She needs to spend considerable time talking about her messages away from the cameras - preferably with a coach who can inspire her to open up her personality and connect with her passion.

It's what we say to our clients: if you're prepared, it won't be an ordeal for you. It's because you leave it to the last moment you don't back yourself. Really it's about getting really comfortable and focused on your values and talking about them in an authentic way.

But Bennett doesn't look like she is ready to back herself. Voters are already forming impressions of her because of interviews like her car-crash on LBC. As they watch her displaying a lack of both warmth and bravado, they're perfectly within their rights to wonder why she's not ready.

Nick Smallman is chief executive of communications training firm Working Voices