Senior attended six elementary schools before going to Manchester Grammar School; he then attended Balliol College, Oxford. In 1937 he joined the editorial staff of the Manchester Guardian. After working as a leader writer, reporter and bridge correspondent, he began to specialise in planning matters, where he built up a reputation as a distinguished specialist journalist. Senior studied the disputes between Manchester City Council and the Cheshire authorities over overspill housing very closely.
In 1956, commissioned by Cambridgeshire County Planning Department, he wrote "A Guide to the Cambridge Plan" which explained the detailed planning document in non-technical language. That year he was made an Honorary Associate Member of the Royal Town Planning Institute.
In 1960, Senior left the staff of The Guardian (as it had then become) and became a freelance. He also worked for the Civic Trust. At the national conference of the Town and Country Planning Association in December 1964, he spoke in favour of the "City Region" as being the only way to make regional planning effective. The next year, he expanded on this theme in a high-profile article in The Political Quarterly, followed by a book of conference papers called "The Regional City".
Senior was named as a member of the Royal Commission on Local Government in England in May 1966. The proceedings of the Royal Commission were kept confidential, but when it was published on 11 June 1969, the Report was found to include a memorandum of dissent by Senior as long as the main report itself.
Memorandum of dissent
The main basis of Senior's dissent was his belief in retaining two tiers of local government. He proposed to create 35 city regions as the upper tier, with 148 directly elected district councils below them. He also advocated indirectly elected regional councils. Observers noted that the boundaries proposed by Senior paid little regard to those existing.
However, Senior's dissent had little impact on the public debate about the report. Senior's appearances at many conferences failed to generate support. In his history of the reform of local government, Bruce Wood comments that "Senior's package was too complex to be readily communicable .. and too radical to be readily acceptable".
After his duties on the Royal Commission ended, Senior returned to the field of planning. An essay he contributed to "London Under Stress" in 1970 called for more families to be resettled outside London to improve life inside; he wanted this move planned by an authority covering an area larger than the Greater London Council. In 1975 he was invited by the Herefordshire Survival Campaign to investigate local government arrangements in Hereford and Worcester, his alternative to be put to a referendum to oppose the merger of the two counties which had recently taken place. He served as a member of Basildon Development Corporation between 1975 and 1979.
Senior continued to support regional government, speaking in favour at a meeting of Labour members of the Association of District Councils in June 1976, and arguing that October that devolution to Scotland risked being defeated by an English backlash unless there was a firm commitment to devolution to the English regions. In 1980 he opposed the choice of Stansted for London's third airport over Maplin, pointing to the loss of agricultural land and the greater investment in housing, roads and infrastructure needed.
- 'SENIOR, Derek', Who Was Who, A & C Black, 1920–2008; online edn, Oxford University Press, Dec 2007, accessed 26 May 2009.
- "The dissenter", Times Diary, The Times, 12 June 1969, p. 8.
- Bruce Wood, "The Process of Local Government Reform 1966–74", George Allen & Unwin, 1976, p. 42.
- "Cambridge Plan Booklet", The Times, 2 October 1956, p. 13. Prior to this in 1945 he wrote an abridged edition of the "City of Manchester Plan".
- "Birmingham Area Needs 18 New Towns By 1986", The Times, 2 December 1964, p. 7.
- See D. Senior, "The City Region as an Administrative Unit", Political Quarterly, vol. 36 no. 1 (1965), pp. 82–91.
- Bruce Wood, "The Process of Local Government Reform 1966–74", George Allen & Unwin, 1976, p. 42-3.
- "Tasks set for new planners of local government: Members of royal commissions named", The Times, 25 May 1966, p. 14.
- "Local England" (Editorial), The Times, 12 June 1969, p. 9.
- Bruce Wood, "The Process of Local Government Reform 1966–74", George Allen & Unwin, 1976, p. 67-9.
- Bruce Wood, "The Process of Local Government Reform 1966–74", George Allen & Unwin, 1976, p. 83-4.
- Bruce Wood, "The Process of Local Government Reform 1966–74", George Allen & Unwin, 1976, p. 69.
- "Planners condemn fatal flaws of local government", The Times, 6 October 1970, p. 4.
- "Referendum on county merger", The Times, 1 September 1975, p. 12.
- Christopher Warman, "Suggestions for English devolution given firm support by Labour district councillors", The Times, 26 June 1976, p. 2.
- John Chartres, "Regional devolution plans 'by Christmas'", The Times, 23 October 1976, p. 2.
- "Hidden costs 'ignored' in Stansted choice", The Times, 6 February 1980, p. 4.