I labour up to the island (4)
I believe the answer is:
bali
'the island' is the definition.
(Bali is an example)
'i labour up' is the wordplay.
'labour' becomes 'lab'.
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'i'+'lab'='ilab'
'ilab' backwards is 'BALI'.
'to' is the link.
(Other definitions for bali that I've seen before include "Middle East country" , "Indonesian holiday destination" , "Island in Indonesia" , "Bail out of the island" , "Holiday island to the east of Java" .)