Section 979. Right of offeror to buy out minority shareholder ...

(2) If the offeror has, by virtue of acceptances of the offer, acquired or unconditionally contracted to acquire—

(a) not less than 90% in value of the shares to which the offer relates, and

(b) in a case where the shares to which the offer relates are voting shares, not less than 90% of the voting rights carried by those shares,

he may give notice to the holder of any shares to which the offer relates which the offeror has not acquired or unconditionally contracted to acquire that he desires to acquire those shares.

...

Section 983. Right of minority shareholder to be bought out by offeror ...

(2) The holder of any voting shares to which the offer relates who has not accepted the offer may require the offeror to acquire those shares if, at any time before the end of the period within which the offer can be accepted—

(a) the offeror has by virtue of acceptances of the offer acquired or unconditionally contracted to acquire some (but not all) of the shares to which the offer relates, and

(b) those shares, with or without any other shares in the company which he has acquired or contracted to acquire (whether unconditionally or subject to conditions being met)—

(i) amount to not less than 90% in value of all the voting shares in the company (or would do so but for section 990(1)), and

(ii) carry not less than 90% of the voting rights in the company (or would do so but for section 990(1)).

...

[NB: The full Companies Act 2006 is available at www.legislation.gov.uk/ukpga/2006/46.]