The New Zealand Seniors Party is planning to take the Government to court for docking overseas pensions.

Under current rules, migrants to New Zealand have their superannuation docked depending on how much they receive from overseas pensions.

Seniors Party member Barnaby Perkins is originally from the UK, and said the rules are unfair.

"We want to have access to pensions which we have paid our own money into. Iv' e been in New Zealand and worked in New Zealand, paid taxes for the last 35, 40 years here."

Around 85 thousand people were affected by the legislation last year.