He disclaimed his peerages in 1964 but never returned to the House of Commons.  , the titles are held by his eldest son, the eleventh Earl, who succeeded in 1995. Lord Sandwich is one of the ninety elected hereditary peers that remain in the House of Lords after the passing of the House of Lords Act 1999, and sits as a cross-bencher. The family seat is today at Mapperton in Dorset. From the 17th century until the 1960s, the family also owned Hinchingbrooke House in Huntingdonshire, from which the title Viscount Hinchingbrooke was derived. Some historical papers of the family and its Hinchingbrooke estate are held by Cambridgeshire Archives and Local Studies at the County Record Office in Huntingdon. The heir apparent is the present holder's elder son, Luke Timothy Charles Montagu, Viscount Hinchingbrooke (b. 1969). The heir apparent's heir apparent is his elder son, The Hon. William James Hayman Montagu (b. 2004).