North League ministers snubbed Italian Republic Day

All the ministers (Maroni, Bossi, Calderoli) of Northern League (an Italian party) didn't enjoy other institutional rappresentatives in Rome during Republic Day celebrations on 2nd June.
Northern League politicians say they don't feel as italian as "padanian", so the Republic Day is not their party.

My two questions:
1) why did they swear in as Italian Ministers?
2) why they don't give up to their hated italian politician wage?