Mr. Steven Thomas reports

MOUNTAIN PROVINCE DIAMONDS ANNOUNCES LEADERSHIP AND OPERATIONAL UPDATE

Mountain Province Diamonds Inc. president and chief executive officer Mark Wall has resigned from the company to pursue other opportunities. Mr. Wall will remain with the company until Dec. 19, 2025, to ensure a smooth transition.

As reported in the company's news release of Nov. 6, 2025, regarding the company's Q3 (third quarter) results, mining through the transitional phase of the high-grade 5034-NEX orebody has commenced and this material is being processed. In addition, the five-day plant maintenance shutdown was completed during Q3, and the Gahcho Kue (GK) mine is now well positioned for strong performance in Q4 (fourth quarter) 2025 and 2026.

The board of directors, together with its nomination committee, will commence a process to fill the role of president and CEO. The company will provide an update in due course.

Jonathan Comerford, the company's chairman, commented:

"On behalf of the board, I would like to thank Mark for his substantial contribution to the company and the operations of the GK mine over the past four years, during what has been a very challenging period for both the company and the diamond industry as a whole. We wish him every success in his future endeavours."

About Mountain Province Diamonds Inc.

Mountain Province is a 49-per-cent participant with De Beers Canada in the Gahcho Kue diamond mine, located in Canada's Northwest Territories. The Gahcho Kue joint venture property consists of several kimberlites that are actively being mined, developed and explored for future development. The company also controls more than 96,000 hectares of highly prospective mineral claims and leases surrounding the Gahcho Kue mine that include an indicated mineral resource for the Kelvin kimberlite and inferred mineral resources for the Faraday kimberlites. Kelvin is estimated to contain 13.62 million carats (ct) in 8.50 million tonnes (t) at a grade of 1.60 carats per tonne and a value of $63 (U.S.) per carat. Faraday 2 is estimated to contain 5.45 million carats in 2.07 million tonnes at a grade of 2.63 carats per tonne and a value of $140 (U.S.) per carat. Faraday 1-3 is estimated to contain 1.90 million carats in 1.87 million tonnes at a grade of 1.04 carats per tonne and a value of $75 (U.S.) per carat. All resource estimations are based on a one-millimetre (mm) diamond size bottom cut-off.

Qualified persons

The disclosure in this news release of scientific and technical information regarding Mountain Province's mineral properties has been reviewed and approved by Tom McCandless, PhD, PGeo, and Tysen Hantelmann, PEng, independent advisers to the company and qualified persons as defined by National Instrument 43-101, Standards of Disclosure for Mineral Projects.

We seek Safe Harbor.