What is the pensions triple lock and why is it controversial?

Andy Burnham is expected to address the triple lock in his speech (Picture: Ian Forsyth/Getty Images)For the past 15 years, the annual rise in the state pension has been decided using a formula known as the triple lock.You might not expect pension policy to generate much heat and anger – but with the triple lock, things are different.To its supporters, the scheme has been vital for bringing the British state pension closer to similar economies in terms of generosity, and that work is stil