“(2) The Minister may at any time on his own motion and at his discretion revoke or suspend for such period as he shall think proper a merchandise licence—

( a) on the ground that, in his opinion, there has been a breach of or a failure to observe or comply with a condition attached to the licence,

( b) on the ground that the holder has been convicted of an offence (whether under this or any other Act) in relation to the business to which the licence relates or a vehicle used in such business,

( c) if the holder ceases to comply with any relevant requirement specified or referred to in regulations under the European Communities Act, 1972, or

( d) on the ground that, in his opinion, there has been a failure to comply with a relevant provision of this Act or of regulations made thereunder.”.