Spanish Well Intervention Update

For Immediate Release  26 May 2011

LENI GAS AND OIL PLC

("LGO" or the "Company")

Spanish Well Intervention Update

Leni Gas & Oil plc, the AIM listed international oil and gas production, development and exploration Company, today announces further details of the well work-over operations being performed at its 100% owned Ayoluengo and Hontomin Oilfields in Northern Spain.

As planned, Société de Maintenance Pétrolière ("SMP") and Services Pétrolièrs Schlumberger ("Schlumberger") were mobilised to the field in the week of the 26th April 2011. The SMP-2 rig and the Schlumberger wireline unit have been used in tandem with the Company-owned Cardwell work-over rig to advance work on two wells simultaneously.

As previously announced in March, the work programme is focussed on six high productivity wells in the central area of the Ayoluengo Field (Ayo-4, 5, 32, 36, 37and 46) and will additionally include the perforation of approximately 40 metres of previously untapped reservoir in the Hontomin-2 well on the nearby Hontomin Field.

To date, wells Ayo-4, Ayo-5 and Ayo-32 have been logged. Wells Ayo-4 and 5 have been perforated and both have been recompleted for production. In well Ayo-4 a total of 23.7 metres of new perforations were added and 25.2 metres of existing open perforations re-perforated. In well Ayo-5 new and repeat perforations were 16.9 and 19.9 metres respectively. Re-perforation is intended to help remove scale build-up and increase the area of contact between the reservoir and the well bore.

Wells Ayo-4 and 5 have been returned to production and the completion of Ayo-32 is expected to be concluded within a week. Well Ayo-5 continues to clean up, stable flow rates have not yet been measured, however, based on the electric logs run in the well it is believed that additional production capacity will be achieved over the next few weeks. Well Ayo-4 was placed back on production on the 25 May 2011 and production data is not yet available.

The SMP-2 rig has now been moved to well Ayo-37 and operations are underway with 5 metres of new perforations and at least 28 metres of re-perforating planned. Additionally, an electric down-hole submersible pump will be installed in well Ayo-37 when logging and perforation operations have been completed. The CPS Cardwell rig will shortly be moved to Hontomin-2 to prepare the well for perforating.

Neil Ritson, LGO Chief Executive commented:

 "We are very happy with our progress so far and remain on time and budget with about 45% of the programme completed. It is too early to predict the production impact of the work, however, the amount of previously untested net pay we have been able to access is slightly more than was estimated in the initial plan."

A further update will be released by the Company at the conclusion of the intervention work.

Competent Person's Statement:

The information contained in this announcement has been reviewed and approved by Neil Ritson, Chief Executive Officer and Director for Leni Gas & Oil Plc who has 35 years of relevant experience in the oil industry. Mr. Ritson is a member of the Society of Petroleum Engineers, an Active Member of the American Association of Petroleum Geologists and is a Fellow of the Geological Society of London.

Enquiries:

Leni Gas & Oil plc

David Lenigas, Executive Chairman

Neil Ritson, Chief Executive Officer

Tel +44 (0) 20 7016 5103

Panmure Gordon plc

Katherine Roe / Hannah Woodley

Tel +44 (0)20 7459 5744

Beaumont Cornish Limited

Roland Cornish / Rosalind Hill Abrahams

Tel +44 (0) 20 7628 3396

Pelham Bell Pottinger

Mark Antelme / Henry Lerwill

Tel + 44 (0)20 7861 3232

NOTES TO EDITORS

Leni Gas & Oil Plc is an international oil and gas exploration, development and production company headquartered in London, trading on the London Stock Exchange's AIM index. LGO's strategy is to acquire projects and businesses within the oil and gas sector that contain a development premium which can be unlocked through a combination of financial, commercial, and technical expertise.

LGO operates a low risk portfolio of production expansion assets in the US Gulf of Mexico, Spain and Trinidad, and holds non-operated exploration acreage Malta. LGO's assets have significant play upside using strategies which leverage novel extraction technologies and proven production enhancement techniques. LGO specifically targets near term production with upside exploitation potential and manages its portfolio to ensure all assets have accelerated incremental reserves and production enhancement programmes.

 Glossary:

bopd - barrels of oil per day