Forget the polls. Gbp/Usd chart tells us what is likely to happen
The pound is very cheap right now. Historicaly we are at the inferior level of the 14 years trading range. We can see multiple false breakouts of this lower suport level followed by sharp rises.
If UK votes tomorrow to leave the European Union it will really be a shock and its consequences will be global, long lasting and difficult to anticipate.
UK did somenthing similar in 1992 when it broke the ERM treaty but there were very different conditions (no vote) and the blame can be put on Germany as well as UK. A "leave" vote would be something never seen so far and this is why it is less likely to happen. If it does, will bring huge risks but equal oportunities.