Definitely insulated bag with ice packs.. transfer milk to storage bags. Or if you have enough at home then pump and dump.
Thanks both x any tips for sterilising the pump after the first use pleasee?
You don't need to sterilise after every use, hot soapy water is enough or you could use the Milton wipes probably?
Breast milk is fine for 6 hours out the fridge. Otherwise you could try an insulated bag with ice packs? X