In the latest of her State of the Nation blogs, Rosie Carter asks what drives those voters who decide in the last moments of the campaign.

It’s the final hours of the election, when many people will be making up their minds about where they’ll draw their cross, and if they will at all. With our data showing fewer than 10% of people who identify strongly with any of the main political parties, there’s all to play for. These undecided voters are the people all of the parties most want to speak to , as they hammer home their slogans on repeat.

What people see as the most important issue facing themselves and their family is often circumstantial and shifts over time. Our data has tracked people’s most important issues over the last 18 months, and while health and Britain leaving the EU remain the most significant issues for the majority of people, immigration has fallen dramatically down the list. Extinction rebellion and the work of David Attenborough have helped to raise the profile of climate change, ensuring that concerns about the environment shot up on the public agenda, from 18% listing the environment in their most important issues in July 2018 to 27% in May 2019. But what issues people see as important won’t always determine how they make their decision.

The messages of this final week will be heard through a lens built up over time. People’s priorities depend on life cycle, whether you have kids or not, what happens in your neighbourhood, what you do for work, even whether you drive or catch the bus to work. This lens reflects what matters most their day-to-day lives, which is why issues like the economy, which feel distant to many, is less of a public priority.

Moreover, these often hyperlocal issues are shone through a broader worldview, so that people are more likely to pick up on messaging that resonates with what they already think, suggesting that people won’t be won over by policies alone.

For example, although a large proportion of people see health and the NHS as their most important issues, how they can express this politically depends on their position on Brexit. Those with a strong Leave identity are most likely to be optimistic that by leaving the EU there will be more money available for the health service, while those who identify most as remainers think Brexit would jeopardise the NHS. It may also depend on local factors, like the closure of a local service, and for those who see immigration negatively, restrictions on immigration offer an answer to their healthcare concerns.

Fundamentally, how people will come to their final decisions in this election is about trust and those seen to have broken trust, with many feeling let down by the political parties, further frustrated by delays to Brexit and angry about things not going their way.

“I don’t think any of them deserve my vote, there’s no trust really, we’re all in limbo, we don’t know where we’re going or what’s going to happen. I think it depends who the leader is, whoever is the leader at that time”

Labour Leave voter, Pontefract

But who is seen to be a good leader, or as a trustworthy one, doesn’t just depend on the stories that are told about them as these are passed through this lens of what matters most.

For people who cared most about Brexit, it was their views on Brexit that led them to think some politicians were more trustworthy than others. A strong stance on Brexit paints political figures as having conviction, which could carry over to other policy areas. If a candidate seemed like they’d try their best to ‘get the job done’ on Brexit, those with strong leave identities were more likely to believe that they would also deliver on their other promises.

But we also found that people could change their minds. People are most likely to trust information that comes by word of mouth, from people they trust, and hearing anecdotes, or hearing others in focus groups share things they had picked up in the news, was often enough to change their minds.

“When I first came in this room, I was right and everyone else was wrong, but now you’ve given me food for thought I’m not so sure”

Leave voter, Swindon

People might be unsure, but how they see all the main political parties is something that’s built up over years, framed by personal experiences and mixed with media narratives about national leaders. Repeating policy promises and slogans alone won’t win over people on the fence.