Judicial Review period expiry and DFS timing

2 December 2015

Sirius Minerals Plc

Judicial Review period expiry and DFS timing

§ Judicial Review periods for all key planning approvals have now ended

§ Company unaware of any challenge to the National Park Authority decision

§ Other local approvals granted to date beyond challenge

§ Definitive Feasibility Study ("DFS") results to be announced to market in January 2016

The Directors of Sirius Minerals Plc (AIM: SXX, OTCQX: SRUXY) ("Sirius" or the "Company") confirm that all key town and country planning approvals for its York Potash Project (the "Project") have passed through their respective Judicial Review ("JR") windows. This is a period during which parties can challenge the validity of the decision on legal grounds (not the merits of the planning decision itself).

Chris Fraser, Managing Director and CEO of Sirius, comments:

"We are pleased to be able to put the majority of the approvals work behind us and focus on the implementation of this world class Project. The DFS is close to completion and we look forward to announcing its positive findings in January 2016."

Further to the announcement on 20 October 2015 and receipt of the Decision Notice from the North York Moors National Park Authority ("the Authority"), which formally granted planning permission for the Company's mine and mineral transport system, the six week JR period for this decision has now passed.

Any JR would have needed to have been submitted to the High Court in a timely fashion and before the end of Monday 30 November 2015. The Authority has confirmed that it has not been notified of any application for a JR having been submitted.

It should be noted that any party involved would technically have until the end of 7 December 2015 to notify the Authority that a valid application had been submitted within the required time period. The Company has had no indication of any JR having been lodged and at this late stage it believes this to be highly unlikely. If one comes to light prior to 9 December 2015, the Company will update the market accordingly.

The JR periods for the other approvals also passed some time ago and are now beyond legal challenge. The other approvals were for the mine and mineral transport system and the materials handling facility from Redcar and Cleveland Borough Council and the operational and construction park and ride facilities.

Definitive Feasibility Study timing

The Company is currently finalising the DFS for the Project. The background work for the DFS has been completed and the Company and its Project Study Manager are currently conducting internal reviews of the DFS pending its finalisation. In parallel to the DFS the Company has continued its value engineering work with shortlisted contractors in preparation for construction. As part of that optimisation work to further refine the design of the Project the Company has conducted a re-tendering exercise with the contractors. The results of this process provide key inputs into the finalisation of the DFS.

The Company expects to complete the DFS early in the New Year and will publish the material findings of the DFS in January 2016. The financing strategy also continues to be advanced with discussions with financing partners expected to be further progressed following the publication of the DFS results.

For further information, please contact:

About Sirius Minerals Plc

Sirius Minerals is the fertilizer development company focused on the development of the York Potash Project in the United Kingdom, which has the world's largest and highest grade deposit of polyhalite, a multi-nutrient form of potash containing potassium, sulphur, magnesium and calcium. Incorporated in 2003, Sirius Minerals' shares are traded on the London Stock Exchange's AIM market. Its shares are also traded in the United States on the OTCQX through a sponsored ADR facility. Further information on the Company can be found at: www.siriusminerals.com.