Mountain Province Diamonds Announces First Quarter 2026 Production and Sales Results, Details of First Quarter 2026 Earnings Release, and Conference Call and board change

Press Release

TORONTO, April 30, 2026  – Mountain Province Diamonds Inc. (“Mountain Province”, the “Company”) (TSX: MPVD) (OTC: MPVD) today announces production and sales results for the first quarter ended March 31, 2026 (“the Quarter” or “Q1 2026”) from the Gahcho Kué Diamond Mine (“GK Mine”). All figures are expressed in Canadian dollars unless otherwise noted.

Q1 2026 Production Takeaways
(all figures reported on a 100% basis unless otherwise stated)

• 2,006,135 carats recovered, a 163% increase compared to Q1 2025 (762,978 carats)
• 2.64 average grade of carats per tonne, a 222% increase compared to Q1 2025 (0.82 carats per tonne)
• 741,480 ore tonnes mined; compares to Q1 2025 ( 0 (nil) ore tonnes mined), as all ore treated came from the stockpile in Q1 2025.
• 759,248 ore tonnes treated, an 18% decrease compared to Q1 2025: (925,773 tonnes treated)

Q1 2026 Production Figures
	2026 Q1	2025 Q1		YoY Variance
Total tonnes mined (ore and waste)	6,203,325	10,092,470		-39 %
Ore tonnes mined	741,480	0		N/A
Ore tonnes treated	759,248	925,773		-18 %
Carats recovered	2,006,135	762,978		163 %
Carats recovered (49% share)	983,006	373,859		163 %
Recovered grade (carats per tonne)	2.64	0.82		222 %

Q1 2026 Sales Results

In the Quarter, 858,173 carats were sold for $40 million (US$29.2million), averaging $47 per carat (US$34 per carat). In Q1 2025, 426,268 carats were sold for $44 million (US$30.7 million), averaging $103 per carat (US$72 per carat).

Further to our news release of March 17, 2026 however, the proceeds of the Company’s diamond sales are paid directly to De Beers Canada Inc. (“De Beers”) pursuant to in-kind election notices previously delivered, and which continue to be delivered, in accordance with the amended and restated joint venture agreement between the Company and De Beers dated March 18, 2025, relating to unpaid cash calls.

Jonathan Comerford, the Company’s President and Chief Executive Officer, commented:

“The first quarter of the year is historically a challenging period for operations due to adverse weather conditions, and Q1 2026 was a particularly cold winter at the GK Mine. During the quarter, total tonnes mined declined significantly compared with Q1 2025, primarily due to the joint venture partners’ decision to pause Tuzo waste stripping to conserve cash, preserve liquidity, and maintain strategic optionality.

Despite these headwinds, Q1 2026 was a record quarter for the mine, with more than 2.0 million carats recovered for the first time. This was achieved at a very high recovered grade of 2.64 carats per tonne. While the grade exceeded expectations, a significant portion of the higher–grade material was in smaller stone sizes, which are currently under the greatest pressure in the diamond market. This explains much of the decline in the average value per carat reported for the period.

As noted in our year–end results commentary, the diamond market continues to be adversely affected by geopolitical uncertainty, including concerns surrounding US tariffs and the ongoing conflict in the Middle East. As previously reported, we continue to engage constructively with all stakeholders to navigate this particularly challenging period for the market, which is currently overshadowing a very strong operational performance in terms of carats recovered. We expect to provide a further update on the outcome of these discussions over the coming weeks.”

At the end of the Quarter Jeff Swinoga stepped down from the board given his involvement in several other board positions. “On behalf of the Board, I would like to thank Jeff for his significant contribution to the Company at both the Audit Committee and Board. We wish him every success in his future endeavours.”.

Earnings Release and Conference Call Details

The Company will host its quarterly conference call on Wednesday May 13^th, 2026 at 12:00pm ET (noon). Prior to the conference call, the Company will release Q1 2026 financial results on May 12^th, 2026 after-market.

Conference Call Dial-in Details:

Title: Mountain Province Diamonds Inc Q1 2026 Earnings Conference Call

Conference ID: 72707
Date of call: 05/13/2026
Time of call: 12:00 (noon) Eastern Time
Expected Duration: 60 minutes

Webcast Link: https://app.webinar.net/vAmWJnBJRgB
North American Toll-Free Dial-In Number:    (+1) 888-699-1199
Participant International Dial-In Number:      (+1) 416-945-7677

A replay of the webcast and audio call will be available on the Company’s website.

About Mountain Province Diamonds Inc.

Mountain Province Diamonds is a 49% participant with De Beers Canada in the Gahcho Kué diamond mine located in Canada’s Northwest Territories. The Gahcho Kué 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 Kué 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 (Mct) in 8.50 million tonnes (Mt) at a grade of 1.60 carats/tonne and value of US$63/carat. Faraday 2 is estimated to contain 5.45Mct in 2.07Mt at a grade of 2.63 carats/tonne and value of US$140/ct. Faraday 1-3 is estimated to contain 1.90Mct in 1.87Mt at a grade of 1.04 carats/tonne and value of US$75/carat. All resource estimations are based on a 1mm diamond size bottom cut-off.

For further information on Mountain Province Diamonds and to receive news releases by email, visit the Company’s website at www.mountainprovince.com.

Qualified Person

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, Ph.D., P.Geo, and Tysen Hantelmann, P. Eng., independent advisors to the Company and Qualified Persons as defined by National Instrument 43-101 Standards of Disclosure for Mineral Projects.

For further information: FOR FURTHER INFORMATION, PLEASE CONTACT: Jonathan Comerford, President and CEO, 151 Yonge Street, Suite 1100, Toronto, Ontario, M5C 2W7, Phone: (416) 361-3562, E-mail: info@mountainprovince.com

IBF4