As special adviser to Clegg, Astle was paid an annual salary of £80,000. 
Astle ran the think-tank CentreForum, ' an independent, liberal think-tank seeking to develop evidence based policy solutions to the problems facing Britain,' from 2005 until 2011. Previously, he worked in Bosnia and Kosovo for the United Nations, and before that, as political adviser to the then leader of the Liberal Democrats, Paddy Ashdown MP. Having started working for a Lib Dem MP in 1994, Astle spent six years working his way up in parliament until he found himself in the leader's office in London. 
- The alchemists of liberalism have left their parties behind, guardian.co.uk, 20 June 2011.
- Julian Astle, CentreForum, accessed 10 January 2011.
- Special advisers in post, 30 November 2014 GOV.UK, accessed 28 April 2015
- Top 50 most influential Liberal Democrats 2011: 26-50 The Telegraph, 18 September 2014, accessed 16 October 2014
- Julian Astle, Reports of the Lib Dems’ death have been greatly exaggerated, telegraph.co.uk, 13 April 2011.
- Interview: CentreForum's Julian Astle 2 November 2010, accessed 9 October 2014