Do you know how Britain could solve this issue?

[febgate16]

I think it is so unfair that British citizens can only stay in the USA, Australia and NZ for 90 days without a visa while people from those ----countries can stay in UK for 6 months without a visa.

Legally speaking, what can Britain do to stop this inequality and make them only allowed to stay in the UK for 90 days?

Does anyone know?

The obvious first step would probably be ... contact your elected officials.