Timing the passport renewal

Uk passport

-Work contract and chinese visa expire in 2 months

-UK passport expires in 4 months

Do I,

1. Renew my UK passport now, then renew my work contract onto the new passport

Or

2. Renew my contract, then renew my UK passport and transfer the visa over

My HR cant help with this decision, they are a new school, never had this situation before and dont regularly help with visa anyway

What did you do? Which is the best way?

Thanks for your time