The Prime Minister intervenes in the potential early release of PC Andrew Harper's killers

The Government previously said exempting ‘one or two offenders’ was ‘not possible’, Now Andy Burnham says he has asked the Justice Secretary Alex Norris to look at ways to increase prison capacity . We’re joined by former Prison officer and Governor John Podmore. Also on The World at One, we examine whether new measures announced today to combat "dodgy" vape shops will improve your local high street. And, we hear about archaeological finds that are coming to light because of the drought hitting England and Wales.