Expansion of Management Team

For immediate release: 0700hrs, 17 October 2011

Sirius Minerals Plc

("Sirius" or the "Company")

Expansion of Management Team

The Directors of Sirius Minerals Plc (AIM: SXX, OTCQX: SRUXY), the globally diversified potash development group, are pleased to announce the appointment of Mr Graham Clarke to the position of Operations Director.

Graham Clarke is the current Managing Director of Cleveland Potash Limited, which operates the Boulby Mine in North Yorkshire, the UK's only potash mine. He has spent his entire 26 year career at Boulby. During this time he has served in many roles and has been Managing Director since 2004. This has given him unique insights into all aspects of operating a large-scale potash production facility. In particular, Graham has been instrumental in the commissioning of the Boulby Mine's polyhalite extraction project. Boulby is the only operational polyhalite mine in the world today.

Graham will be one of the key leadership team delivering the York Potash Project. He will also have broader involvement in the development and execution of the Company's global development strategies. He will formally join Sirius in early April 2012 once his notice period with Cleveland Potash has expired.

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

"I am absolutely delighted to announce Graham's appointment to the Company. There is no person better qualified to help us continue the rapid progress of the York Potash Project and to fulfil our goal of becoming one of the world's leading potash producers. Not only is he the only person to successfully commission and oversee a new polyhalite mine, but he lives and breathes for the local area and its wellbeing."

Graham Clarke commented:

"I have been very impressed with the strategy and approach of Sirius and in particular the sense of urgency and innovation ingrained in the Company's culture. The York Potash Project is a fantastic project and the opportunity to join Sirius and help deliver its large-scale production strategy is an opportunity I could not turn down.

"I understand not only the challenges involved but also the huge benefits the York Potash Project can bring to the area and the UK. The operational experience I have of mine development, the local environment and health and safety issues will enable me to help accelerate the York Potash Project towards production.

"I leave Boulby after many happy years and with great gratitude to all the hard working members of staff. There is a strong management team in place to step into my shoes and I look forward to the possibility of working together in the future on key areas of potential cooperation."

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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).

The Company is additionally progressing ongoing Research and Development initiatives into the secondary uses of salt and potash beds for energy storage and carbon dioxide sequestration.

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.