A group of 13 pensioners living in countries including Australia and Canada are calling for the UK Government to change its pensions policy.
Currently, inflation proofing only applies to UK pensioners who live in the European Economic Area or in 15 other countries.
The two-hour hearing will be the latest stage in a long-running legal challenge and the end of the line in the legal process.
The pensioners claim the UK’s rules unfairly discriminate against them, and nearly half a million other expatriate UK pensioners, in breach of the European Convention on Human Rights.
Age Concern head of public policy Andrew Harrop says: “It is hugely unfair that pensioners who have made their National Insurance contributions all their lives in the UK are being penalised for retiring abroad and losing out on the uprating of their pension.
“We hope the case today will see an end to this inequality and ensure the Government gives every pensioner their fair share, no matter where they decide to retire.”