SM3 Preliminary Coring Result

26 March 2012

Sirius Minerals Plc

("Sirius" or the "Company")

SM3 Preliminary Coring Result

§ Intersection through shallower Shelf Seam of polyhalite

§ 22.2 metres of massive polyhalite intersected within a total of 51.4 metres of polyhalite mineralisation

The Directors of Sirius Minerals Plc (AIM: SXX, OTCQX: SRUXY), the globally diversified potash development group, are pleased to announce the completion of coring of the primary hole at SM3 (Raikes Lane), the third new borehole completed at the York Potash Project.

Drilling of SM3 commenced on 5 October 2011 with the smaller top-hole rig drilling and setting casing down to 672m below ground level ("bgl"). Subsequently the larger coring rig arrived at SM3 on 5 February 2012 and coring of the Fordon Evaporite section commenced on 12 March 2012 from 1,417m down to the top of the Kirkham Abbey Formation at 1,650m. Massive polyhalite was intersected between 1,498.3m and 1,520.6m, followed by a zone of mixed polyhalite and halite from 1,520.6m down to 1,549.9m. There was 100% core recovery through both zones.

Chris Fraser, Managing Director and CEO of Sirius said:

"This good result from SM3 continues the solid progress being made at the York Potash Project. SM3 was drilled in the transition zone between the shallower Shelf Seam and the deeper Basin Seam polyhalite deposits and has delivered what appears to be a thick intersection of high-grade polyhalite in the Shelf Seam."

Summary of Preliminary Results - SM3 (collar: 490315 E, 504861 N, 194.9m AOD)

Notes:

1. Depth from sea-level shown due to the varying topography of the York Potash Project drill sites.

2. Thickness based solely on visual and geological interpretation of the key mineralised zones. Assays are required to confirm the thickness interpretation and the potassium grades of the mineralisation.

3. "Massive polyhalite rock" refers to the visual interpretation of the cores as being apparently high purity polyhalite. However, grade can only be confirmed with completion of the assays.

4. Borehole is approximately vertical. Approximate average dip is measured from the core. Wireline logging and gyro survey will determine the actual, true dip.

Although coring of the "mother" hole is complete, work continues on SM3 with wireline logging and a borehole survey, to be followed by the drilling of a deflection 1,213m below surface. This deflection will generate detailed information on lateral continuity of the mineralisation and will provide an additional core of the polyhalite horizon. This is the first planned borehole deflection of the York Potash exploration program.

The SM3 core will be sampled shortly and tests for polyhalite content carried out at the laboratory facilities of the British Geological Survey.

The new coring rig (Rig 16) has now arrived at the York Potash Project. It is undergoing final testing and assembly before being moved to SM6 (Newton House). Once the current coring rig (Rig 5) has completed its work at SM3, it will move to complete SM4 (Gough). SM4 is already drilled to a depth of 747m.

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About Sirius Minerals Plc

Sirius Minerals is a globally diversified potash development company. Its primary focus is to bring on stream major potash mining facilities through the acquisition and development of projects overlying recognised potash deposits. Today it holds properties in the United Kingdom (North Yorkshire), the United States (North Dakota), and Australia (Queensland and Western Australia).

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 the use of a sponsored ADR facility. Further information on the Company can be found at www.siriusminerals.com.

Competent Person's Statement and Risk Statement

The information in this Stock Exchange Announcement that relates to Mineral Exploration results and Exploration Targets, together with any related assessments and interpretations, have been verified by and approved for release by Dr Frederick W. Smith FIMMM., CEng, CSci., a qualified geologist and full-time employee of FWS Consultants Limited ("FWS"), Environmental and Geological Consultants. Dr Smith, who is a Fellow of the Institute of Materials, Minerals and Mining (IMMM), has sufficient experience which is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person for the purposes of the AIM Rules. Dr Smith and FWS consent to the inclusion of the information contained in this announcement and the respective references to them in the form and context in which they appear. The JORC Exploration Target estimates of quantity and grade are conceptual in nature and there has been insufficient exploration to define a Mineral Resource on the property and it is uncertain if further exploration will result in discovery of a Mineral Resource on the Property. The estimates are not a Reserve or Resource statement in accordance with an AIM recognised Standard and should not therefore be relied upon as such. It should be noted that the Pan European Code of Reporting or PERC (that IMMM co-wrote) released in December 2008 and JORC are essentially identical on all key aspects relating to compilation and quoting Exploration Targets.

Qualified Person

Graham Clarke, Operations Director for Sirius Minerals Plc, who has reviewed this update, has over 26 years experience in the potash mining industry. He has a Degree in Mining Engineering from the University of Nottingham and extensive operational experience gained at Cleveland Potash Limited in the mining of the Boulby Potash seam and the exploration and development of the upper Fordon polyhalite seam.