(Gavin) Tobias Alexander Winterbottom HORTON (born 18 II 1947) changed his surname by deed poll from Winterbottom to Horton on 19 March 1976 (see
https://www.thegazette.co.uk/London/issue/46897/page/6780/data.pdf), although he has retained Winterbottom as a christian name; the reason for the change of name was a family inheritance. He is usually known as Toby Horton.
Mr Horton is a nephew of Ian WINTERBOTTOM (6 IV 1913 - 4 VII 1992), MP (Labour) for Nottingham Central from 1950 to 1955, who was created a Life Peer as Baron Winterbottom on 14 May 1965. He is also a first cousin once removed downwards of William Rodney WINTERBOTTOM (18 IX 1894 - 25 VII 1937), whose first of three marriages was to (as her first of four husbands) Mary Reeve WARD (6 VI 1902 - 13 IX 1976), whose third husband, the 9th Earl of Essex, was a step first cousin once removed upwards of Mr Horton's wife, née the Hon Fiona Catherine Peake.