What's causing the petrol shortage?

<div>First gas, now petrol. The strange thing is there is no actual lack of petrol just a dearth of drivers to bring it to the stations. There are differing thoughts as to the reason for this, some say Brexit, others that this is a wider issue. Katy Balls, Isabel Hardman and James Forsyth discuss this as well as what we can expect from this weekend's Labour conference. </div>