Irishmen going to England would say this is similar to Tinder (8)
I believe the answer is:
firewood
'to tinder' is the definition.
(I've seen this before)
'irishmen going to england would say' is the wordplay.
'irishmen going' becomes 'fir' (I can't explain this - if you can you should believe this answer much more).
'to england' becomes 'e'.
'say' indicates a 'sounds like' (homophone) clue.
'would' is a homophone of 'wood'.
'fir'+'e'+'wood'='FIREWOOD'
'this is similar' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for firewood that I've seen before include "Tinder" , "Logs etc for fuel" , "Kindling for 17 across" , "Fuel for the grate" , "Fuel from trees" .)