The UK’s membership of the European Union is the biggest unknown of the year, affecting everything from politics to financial markets.

But how can you tell which way the referendum will go? Here are the three things you should be looking out for:

How do people say they’ll vote?

Polls aren’t always reliable. As we know from the last general election, they don't always reflect public opinion. That's because pollsters only survey a tiny fraction of the population - and people are unreliable. Some lie, some will change their minds, while others may never vote at all.

Despite this, they’re still one of the best gauges we have as to how the British public will vote in the forthcoming referendum on EU membership.

Of the dozens of polls released since the start of the year, the results have been mixed. Yet in recent weeks, several results have suggested that the UK will vote to withdraw from the political union.

If you look at a poll of polls - which takes the average of a group of polls - what was a clear lead for the remain camp has been eroded. However, support for leaving the EU has only recently been coming out on top.