There has been much justified condemnation of the daft "Policy Exchange" report "Cities Unlimited" which appeared to suggest that regenerating the north of England is a waste of time and that Northerners should move to the south instead.
It was wrongly suggested by Labour politicians and their friends in the media that the authors of this report were close to David Cameron. In fact he rejected it in the most emphatic terms on Wednesday as reported here in an earlier post.
Indeed, of any of the three main party leaders have to distance themselves from the report it is Nick Clegg, the Liberal Democrat leader, who is currently on holiday in Spain.
For it turns out that both of the report's co-authors are or have close links with the Liberal Democrats.
Oliver Marc Hartwich - Policy Exchange's chief economist - lists on his official biography that he used to work for Lib Dem peer, Lord Oakeshott.
And his co-author, Tim Leunig, remains an adviser to the Liberal Democrats, a regular contributor to the Lib Dem Voice blog and even appears campaigning on the website of Ed Davey, his local Lib Dem MP.
This was pointed out by the Daily Telegraph, who also report a "red-faced Lib Dem spokesman" as saying that the views in the report "do not reflect those of the Liberal Democrats."