(1)The power of a court in any part of the United Kingdom to order that the term of any sentence of imprisonment or detention passed by the court shall commence at or before the expiration of another term of imprisonment or detention shall include power to make such an order where that other term was imposed by sentence of a court elsewhere in the United Kingdom or in any of the Channel Islands or the Isle of Man if the offender—
(a)is serving that other sentence in that part of the United Kingdom; or
(b)is for the time being present in that part of the United Kingdom,
by virtue of an order under this Part of this Act, or is unlawfully at large under the law of the country in which that other sentence was passed.
(2)The provisions of this section shall be without prejudice to the powers exercisable by any court apart from those provisions.