POWER OF ATTORNEY


I, Philip N. Duff, do hereby nominate, constitute and appoint
each of Anne Gill Kelly, Gregg L. Bienstock, Patricia Lo Cascio,
and Stacey B. Spain as my true and lawful agent and
attorney-in-fact, with full power and authority to act
hereunder, in his or her
discretion, in my name and on my behalf as fully as I could if
I were present and acting in person, to make any and all required
or voluntary filings under Section 16(a) of the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and
the applicable +rules and regulations thereunder, with the
Securities and Exchange Commission, the New York Stock Exchange,
Ambac Financial Group, Inc., a Delaware corporation (the "Company"),
and any other person or entity to which such filings may be
required under Section 16(a) of the Exchange Act as a result
of my service as an officer of the Company or beneficial
ownership (within the meaning of Section 16(a) of the
Exchange Act) of more than ten percent of any class
of equity securities of the Company.

I hereby consent to, ratify and confirm all that each
said attorney-in-fact shall do or cause to be done
by virtue of this Power of Attorney.  I hereby
acknowledge that each attorney-in-fact, in serving
in such capacity at my request, is not assuming,
nor is the Company assuming, any of my responsibilities
to comply with Section 16 of the Exchange Act.

This Power of Attorney shall remain in full force and
effect from this date forward for so long as I am
an officer or director of the Company and for such
time thereafter as may be necessary to make any such
filings or until revoked or modified by me. I hereby
revoke all prior powers of attorney relating to the
foregoing acts.

IN WITNESS WHEREOF, I have hereunto signed my name
this 12th day of April 2007.




/s/Philip N. Duff
PHILIP N. DUFF