[2] In 1966 he took leave from his academic career to take up the role of Director-General of Economic Planning at the Ministry of Transport, serving as a special adviser to Cabinet minister Barbara Castle.
He was also close to several other leading Labour politicians, working alongside the likes of Anthony Crosland, Richard Marsh, and Peter Shore.
He sat on several private and public sector boards including the Audit Commission, the ESRC, the London Docklands Development Corporation and the Megaw Committee on Civil Service Pay.
On 25 November 2007, Foster gave an outspoken interview to Rachel Sylvester and Alice Thomson of The Daily Telegraph attacking Tony Blair as the 'worst Prime Minister since Lord North' in terms of how he managed government.
The Telegraph revealed that "Government departments have "serious deficiencies"; the combined output of Parliament and the executive contain "too many disappointments and failures"; and "emphasis on 'management' has led to more bureaucracy at the expense of substance" in the Foreign Office.