Sure, apologies for delay, was away on holiday and I left you questioning your indefatigability (which I salute)!
Grauniad summary: https://www.theguardian.com/news/datablog/2012/mar/27/public-private-sector-pay
ONS publication : https://webarchive.nationalarchives.gov.uk/ukgwa/20160107050914/http://www.ons.gov.uk/ons/rel/lmac/public-and-private-sector-earnings/2012/estimating-differences-in-public-and-private-sector-pay.html#tab-Differences-between-the-public-and-private-sectors
Due an update this year so we can shortly have the same argument over again, which I know you love!