NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION (DIRECTLY OR INDIRECTLY) IN WHOLE OR IN PART IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION.

FOR IMMEDIATE RELEASE

15 June 2026

Union Jack Oil plc

("Union Jack" or the "Company")

Rule 2.9 Announcement

In accordance with Rule 2.9 of The City Code on Takeovers and Mergers (the "Code"), Union Jack confirms that, as at the date and time of this announcement, it has 152,846,420 ordinary shares of 5 pence each in issue. The Company holds 6,300,000 shares in Treasury, consequently the total voting rights comprise 146,546,420 ordinary shares which are admitted to trading on the AIM Market of the London Stock Exchange.

The International Securities Identification Number (ISIN) for the Company's ordinary shares is GB00BLH1S316 and the Company's LEI number is 2138005VW7IUUUPY5Q88.

For further information, please contact:

Union Jack Oil plc                                                    [email protected]

David Bramhill

SP Angel Corporate Finance LLP                           +44 (0)20 3470 0470

Nominated Adviser and Joint Broker

Matthew Johnson

Richard Hail

Jen Clarke

Zeus Capital Limited                                                            +44 (0)20 3829 5000

Joint Broker

Antonio Bossi

Simon Johnson

George Duxberry

Gneiss Energy Limited                                            + 44 (0)20 3983 9263

Financial Adviser

Jon Fitzpatrick

Luke Kanczes

Nicholas Barnett

Harbour Access                                                        +1 (475) 477 9402

USA Investor Relations

Jonathan Paterson

Important Notice

SP Angel Corporate Finance LLP ("SP Angel"), which is authorised and regulated by the Financial Conduct Authority, is acting exclusively for the Company in relation to the possible offer for the Company and is not acting for any other person in relation to such possible offer for the Company. SP Angel will not be responsible to anyone other than the Company for providing the protections afforded to its clients or for providing advice in relation to the contents of this announcement or any possible offer for the Company or arrangement referred to herein.

Gneiss Energy Limited ("Gneiss Energy"), which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for the Company in relation to the possible offer for the Company and is not acting for any other person in relation to such possible offer for the Company. Gneiss Energy Limited will not be responsible to anyone other than the Company for providing the protections afforded to its clients or for providing advice in relation to the contents of this announcement or any possible offer for the Company or arrangement referred to herein.

Zeus Capital Limited which is authorised and regulated in the United Kingdom by the Financial Conduct Authority, is acting exclusively for the Company as joint broker and no-one else in connection with the possible transaction described in this announcement and accordingly will not be responsible to anyone other than the Company for providing the protections afforded to clients of Zeus Capital Limited nor for providing advice in relation to the matters described in this announcement. Neither Zeus Capital Limited nor any of its affiliates owes or accepts any duty, liability or responsibility whatsoever (whether direct or indirect, whether in contract, in tort, under statute or otherwise) to any person who is not a client of Zeus Capital Limited in connection with the matters referred to in this announcement, any statement contained herein or otherwise.

Disclosure requirements of the Takeover Code (the "Code")

Under Rule 8.3(a) of the Code, any person who is interested in 1% or more of any class of relevant securities of an offeree company or of any securities exchange offeror (being any offeror other than an offeror in respect of which it has been announced that its offer is, or is likely to be, solely in cash) must make an Opening Position Disclosure following the commencement of the offer period and, if later, following the announcement in which any securities exchange offeror is first identified. An Opening Position Disclosure must contain details of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any securities exchange offeror(s). An Opening Position Disclosure by a person to whom Rule 8.3(a) applies must be made by no later than 3.30 pm (London time) on the 10th business day following the commencement of the offer period and, if appropriate, by no later than 3.30 pm (London time) on the 10th business day following the announcement in which any securities exchange offeror is first identified. Relevant persons who deal in the relevant securities of the offeree company or of a securities exchange offeror prior to the deadline for making an Opening Position Disclosure must instead make a Dealing Disclosure.

Under Rule 8.3(b) of the Code, any person who is, or becomes, interested in 1% or more of any class of relevant securities of the offeree company or of any securities exchange offeror must make a Dealing Disclosure if the person deals in any relevant securities of the offeree company or of any securities exchange offeror. A Dealing Disclosure must contain details of the dealing concerned and of the person's interests and short positions in, and rights to subscribe for, any relevant securities of each of (i) the offeree company and (ii) any securities exchange offeror(s), save to the extent that these details have previously been disclosed under Rule 8. A Dealing Disclosure by a person to whom Rule 8.3(b) applies must be made by no later than 3.30 pm (London time) on the business day following the date of the relevant dealing.

If two or more persons act together pursuant to an agreement or understanding, whether formal or informal, to acquire or control an interest in relevant securities of an offeree company or a securities exchange offeror, they will be deemed to be a single person for the purpose of Rule 8.3.

Opening Position Disclosures must also be made by the offeree company and by any offeror and Dealing Disclosures must also be made by the offeree company, by any offeror and by any persons acting in concert with any of them (see Rules 8.1, 8.2 and 8.4).

Details of the offeree and offeror companies in respect of whose relevant securities Opening Position Disclosures and Dealing Disclosures must be made can be found in the Disclosure Table on the Takeover Panel's website at www.thetakeoverpanel.org.uk, including details of the number of relevant securities in issue, when the offer period commenced and when any offeror was first identified. You should contact the Panel's Market Surveillance Unit on +44 (0)20 7638 0129 if you are in any doubt as to whether you are required to make an Opening Position Disclosure or a Dealing Disclosure.

Publication on Website

In accordance with Rule 26.1 of the Code, a copy of this announcement will be made available, subject to certain restrictions relating to persons resident in restricted jurisdictions, on the Company's website at https://unionjackoil.com/ by no later than 12 noon (London time) on 15 June 2026. The content of the website referred to in this announcement is not incorporated into and does not form part of this announcement.