Hi,

It is the Billy boys, (one of the versions) you can find it at Ulster Orange/ Unionist Loyalist songbook along with a lot more of the same.

the rest of the chorus is

surrender or you'll die
for we are the Billy Billy boys

Sung to the tune of "Marching through Georgia".

According to the notes at the link above you "continue to sing the chorus until you are arrested."

Slainte

alison