EXHIBIT 12


                                                     August 26, 2005



Van Kampen Municipal Trust
1 Parkview Plaza
PO Box 5555
Oakbrook Terrace, Illinois 60181-5555

Van Kampen Investment Grade Municipal Trust
1 Parkview Plaza
PO Box 5555
Oakbrook Terrace, Illinois 60181-5555

Ladies and Gentlemen:

         We have acted as special counsel to the Van Kampen Municipal Trust (the
"Acquiring Fund"), a closed-end management investment company organized as a
Massachusetts business trust, and to the Van Kampen Investment Grade Municipal
Trust (the "Target Fund"), a closed-end management investment company organized
as a Massachusetts business trust, in connection with (i) the acquisition by the
Acquiring Fund of all of the assets of the Target Fund, solely in exchange for
common shares of beneficial interest of the Acquiring Fund, par value $0.01 per
share, auction preferred shares of the Acquiring Fund, par value of $0.01 per
share and with a liquidation preference of $25,000 per share, and the assumption
by the Acquiring Fund of all of the liabilities of the Target Fund and (ii) the
subsequent liquidation of the Target Fund (collectively, the "Reorganization"),
pursuant to the Agreement and Plan of Reorganization, dated February 3, 2005,
between the Acquiring Fund and the Target Fund (the "Agreement"). You have
requested our opinion regarding whether the Reorganization will be treated for
United States federal income tax purposes as a reorganization qualifying under
Section 368(a) of the Internal Revenue Code of 1986, as amended (the "Code").
Unless otherwise defined, capitalized terms used in this opinion have the
meanings assigned to them in the Agreement.

         In connection with our opinion, we have reviewed originals or copies,
certified or otherwise identified to our satisfaction, of the Agreement, the
Proxy Statement/Prospectus (prepared with respect to the Reorganization), the
Statement of Additional Information (also prepared with respect to the
Reorganization) and such other documents, certificates and records as we have
deemed necessary or appropriate as a basis for the opinion set forth below. We
have assumed that the Reorganization will be consummated in accordance with the
Agreement, the Proxy Statement/Prospectus, the Statement of Additional
Information and such other documents, certificates and records.

         For purposes of our opinion, we have assumed the legal capacity of all
natural persons, the genuineness of all signatures, the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as certified, conformed or photostatic copies and
the authenticity of the originals of such latter documents. We have assumed that
such documents, certificates and records are duly authorized, valid and
enforceable.

         In rendering our opinion, we have also relied upon statements and
representations of officers and other representatives of the Acquiring Fund and
the Target Fund and have assumed that such statements and representations are
and will continue to be correct without regard to any qualification as to
knowledge or belief.

         Our opinion is based on the Code, Treasury regulations, judicial
authorities, published positions of the Internal Revenue Service (the "IRS") and
such other authorities as we have considered relevant, all as in effect as of
the date of this opinion and all of which are subject to change or differing
interpretations (possibly with retroactive effect). A change in the authorities
upon which our opinion is based could affect our conclusions. An opinion of
counsel is not binding on the IRS or any court. No assurance can be given that
the IRS would not assert, or that a court would not sustain, a position contrary
to this opinion.

         Based upon and subject to the foregoing, we are of the opinion that,
for United States federal income tax purposes, the Reorganization will be
treated as a "reorganization" within the meaning of Section 368(a) of the Code.

         Except as set forth above, we express no other opinion. This opinion is
expressed as of the date hereof, and we are under no obligation to supplement or
revise our opinion in order to reflect any changes in applicable law (including
any changes that have retroactive effect) or any information, statement,
representation or assumption relied upon in this opinion that becomes untrue,
incorrect or incomplete. This opinion is delivered to you solely for your
benefit and cannot be relied upon by anyone else without our written consent.



                                                  Very truly yours,


                                    /s/ Skadden, Arps, Slate, Meagher & Flom LLP