Under an arrangement called the “triple lock”, the UK state pension goes up each year by either 2.5%, inflation or earnings growth – whichever is the highest figure.
Not all pensioners who move abroad have their pensions frozen.
The UK has agreements in place with EU countries and the United States, among others, to continue increasing pensions in line with the amount received by UK residents.
Canada, Australia, New Zealand and India are among the countries which do not have agreements.
Campaigners say that creates an injustice.
Patrick Edwards, who lives in Australia and is also part of the End Frozen Pensions campaign, said they had paid in like everyone else but were now being “treated differently merely because of their address”.
“If they lived in many other countries around the world they’d be getting the same as people in the UK but unfairly they’ve been selected as having had their pensions frozen,” he said.
There is diplomatic pressure to change the policy too.
The Canadian government is understood to have raised the issue with the new government already.
The Australian government made repeated representations to the last government and a spokesperson said it would continue to raise it at “appropriate opportunities”.