General election 2017: What is the pensions triple lock?

Labour and the Liberal Democrats have pledged to keep the triple lock on state pensions if they win the general election.

The BBC's Steph McGovern explains who the winners and losers are from the policy.

Correction: The figure of £159.55 in this report refers to the maximum for those who reach state pension age after 6 April 2016. The basic state pension, available to older claimants, is £122.30 a week.