First tab :P

Capo on 5th fret

Intro:

E-----2-0-2-----2-0-2s-7-5-2-5-0-----0-|
B-0-3---------3------------------3-0---|
G-----------3--------------------------|
D--------------------------------------|
A--------------------------------------|
E--------------------------------------|

Instead of the last 3 notes you can play G, F#

First verse:

Bm
We must be shrewd or stupid,
G           F#
One of the two,
Bm
The Stakes are too important,
G         F#
For us to lose,
Bm
But he would have broke your heart,
G                  F#
But she would have lead me down the garden,
Bm
They would always leave,
G            F#
Early in the morning,
G
No final kiss,
F#               G F#
No final warning,

Chorus:

Bm
Just as we're friends today,
G                 F#
Tomorrow we'll be lovers,
Bm                   G        F#
Never to be the same no more, no more,
Bm
We've crossed the Rubicon,
    G                 F#
And we can't turn our heels,
Bm
So it's onto the breach,
         G                 F#
Oh we'll have to teach ourselves, my love,

2nd Verse:

Bm
And I'll be telling tales,
   G              F#
If I, claim to be sure,
Bm
That this will last forever,
     G                      F#
Just look at the way it has gone before,
    Bm
But he would have broke your heart,
    G              F#
And she would have taken me for granted,
Bm                      G            F#
They would always leave early in the morning,
G
No final kiss,
F#           G F#
No final warning

Chorus:

Bm
Just as we're friends today,
G                 F#
Tomorrow we'll be lovers,
Bm                   G      F#
Never to be the same no more,
Bm
We've crossed the Rubicon,
    G                 F#
And we can't turn our heels,
Bm
So it's onto the breach,
                          G          F#
Oh we'll have to teach ourselves, my love.


I'm pretty sure that there is another chord within the song but i can't figure it out. 
melody line played by the lead guitar in the second chorus is similar to the intro but 
a different ending which i haven't worked out yet.