Whole song is done by two young irish lads who use a loop. so this here is a very
look into how to go about it.  Plus I'm pretty sure the main guitarists guitar is tuned 
a
and has a capo on the 2nd fret (cause that's what he said), but i did it by ear without 
a capo. so enjoy and let me know of any possible/probable improvements.

1st Loop
E --------------------|
B -5-5-5-5-5-5-5-5-5--|
G -4-5-5-5-5-5-5-5-5--|   Repeats on loop til the "Ba-Bah" bit
D --------------------|
A --------------------|
E --------------------|

2nd Loop (comes after 8 bars into the intro)
E----2----4----4-----|
B----2----4----5-----|
G----2----4----6-----|  Repeats on loop til the "Ba-Bah" bit
D----2----4----6-----|
A----2----4----4-----|
E----2----4----4-----|

'Wear your conscience like a t-shirt,
Take it off you while you cheat on her,
I'm sure that you're guilt free,
I'm sure, you're not listening.

Making sure that you're not noticed,
Yeah your performance, it's faultless.
I'm sure, you'll get caught out.
With no shadows on your doubts.

(ba-bah)

Well you were the one, that I wanted to be.
You were, my fantasy

Lyrics and tuning details from the band lead singer/guitarist, cheeers!