Yes you can in class G
From the ANO.
Minimum height
33 (1) Subject to paragraphs (2) and (3), an aircraft shall not fly at a height of less than 1,000
feet above the highest obstacle within a distance of 5 nautical miles of the aircraft
unless:
(a) it is necessary for the aircraft to do so in order to take off or land;
(b) the aircraft flies on a route notified for the purposes of this rule;
(c) the aircraft has been otherwise authorised by the competent authority in relation
to the area over which the aircraft is flying; or
(d) the aircraft flies at an altitude not exceeding 3,000 feet above mean sea level and
remains clear of cloud and with the surface in sight and in a flight visibility of at
least 800 metres.
(2) The aircraft shall comply with rule 5.
(3) Paragraph (1) shall not apply to a helicopter that is air-taxiing or conducting
manoeuvres in accordance with rule 6(i).
To be honest I thought that they wrote it that way just for helicopters. I can't see many fixed wing pilots having the balls to do it. And also it gives us hassels in relation to approach bans which can be got round using a none instrument runway. And EU-OPS makes it unusable for commercial flights.