Mountain Province Diamonds Announces Positive Gahcho Kue Independent Feasibility Study

TORONTO AND NEW YORK, September 14, 2010 -

    Shares Issued and Outstanding: 72,344,423
    TSX: MPV
    NYSE AMEX: MDM

Mountain Province Diamonds Inc. ("Mountain Province", the "Company")
(TSX: MPV, NYSE AMEX: MDM) today announced the receipt of the final draft of
an independent feasibility study (the "Study") on the Gahcho Kue diamond
project located in Canada's Northwest Territories. JDS Energy and Mining Inc.
led and prepared the Study, which has been presented to the Gahcho Kue Joint
Venture partners, Mountain Province (49%) and De Beers Canada Inc. (51%).

The Study is currently the subject of a detailed internal review by the
JV partners, which may take up to 90 days, and pursuant to such review is
subject to revision and clarification. The final results may change from
those presented in the Study. Pending the release of the final results,
Mountain Province today announced the following preliminary results:

    - IRR exceeds the minimum 15% required under the Joint Venture
      agreement to support a decision to develop Gahcho Kue;
    - Base Case operating mine life of 11 years based on an average annual
      production of approximately 4.5 million carats;
    - Initial Capital Cost range C$550M to C$650M (inclusive of
      contingencies, but subject to the owner's final review process and
      consideration of any necessary changes); and
    - Cash Operating Cost range C$48 to C$60 per tonne (subject to the
      owner's final review process and consideration of any necessary
      changes or provision for appropriate contingencies).

Commenting, Mountain Province CEO Patrick Evans said: "Mountain Province
believes that the Study delivers an economically viable, technically credible
and environmentally sound, development plan for the Gahcho Kue project. Our
focus now shifts to completion of the Gahcho Kue environmental impact
assessment, which will be filed with the Mackenzie Valley Environmental
Review Board prior to the end of the year."

Qualified Person

The Study was prepared by an integrated engineering team led by JDS
Energy and Mining. Mr. Daniel Johnson, P. Eng has reviewed and approved the
contents of this release.

Located in Canada's Northwest Territories, Gahcho Kue is the largest new
diamond project under development globally. The project consists of a cluster
of kimberlites, three of which have an indicated resource of approximately
30.2 million tonnes grading at 1.67 carats per tonne (approximately 50.5
million carats) and an inferred resource of approximately 6 million tonnes
grading at 1.73 carats per tonne (approximately 10.3 million carats). Mineral
resources that are not mineral reserves do not have demonstrated economic
viability.

Forward-Looking Statement

This news release may contain forward-looking statements, within the
meaning of the "safe-harbor" provisions of the Private Securities Litigation
Reform Act of 1995, regarding the Company's business or financial condition.
Actual results could differ materially from those described in this news
release as a result of numerous factors, some of which are outside the
control of the Company.

For further information: For further information: Mountain Province
Diamonds Inc., Patrick Evans, President and CEO, Phone: +1-416-670-5114,
www.mountainprovince.com, E-mail: info@mountainprovince.com

For further information: For further information: Mountain Province Diamonds Inc., Patrick Evans, President and CEO, Phone: +1-416-670-5114, E-mail: info at mountainprovince.com