A lecturer was deluged with hate mail and had his work branded "politically naive" by a fellow academic after suggesting that regeneration of some British cities is impossible.
Tim Leunig, lecturer in economic history at the London School of Economics, received 40 abusive emails last week in response to a report he wrote for Conservative think-tank Policy Exchange.
The report suggests that citizens of failing northern towns should be told "the reality of the position" on the likelihood of regeneration and encouraged to move to London and the South East.
Dr Leunig said: "I did not really expect people to send me emails saying I am a cocksucker. People have accused me of being a paedophile - both people accusing me have misspelled it. One said I 'took it up the wrong end'. I am particularly surprised since I did not say anything bad about anybody."
Dr Leunig said he did not feel physically threatened despite one correspondent's threat to set fire to him if he visited Liverpool.
Furious northerners have set up anti-Tim Leunig pages on social networking sites such as Facebook and Bebo.
"There are a few comments on Facebook saying I should have gone to Specsavers," he said. "I bought my glasses in 1990 and they are not that fashionable, but I don't care."
Michael Parkinson, director of the European Institute for Urban Affairs at Liverpool John Moores University, branded the report "politically naive".
He said Dr Leunig and co- author James Swaffield, a Policy Exchange researcher, had "bitten off more than they could chew" and that Liverpool's economy was beginning to improve.
Encouraging too much growth in London would mean "the golden goose would asphyxiate itself", the professor suggested.
Dr Leunig maintains that his report was not a call for all northerners to move south. It recommends that a proportion of new homes in economically successful areas should be set aside so that people could - if they chose to - move from less prosperous cities to get work.
"I do not think we should give up on the North and I do not call for any cuts in regeneration funding," he said.
Part of the report had been peer-reviewed in the Oxford Review of Economic Policy in March, he added.
Policy Exchange has close links with Conservative leader David Cameron, who reportedly described the paper as "insane".
Dr Leunig said this was understandable given what he was likely to have read about it in the media.
However, the LSE had been supportive and several colleagues had sent emails wishing him luck, he added.
Despite an offer of free tickets to Liverpool from Virgin Trains and an invitation to visit the city, Dr Leunig said he would not go there for fear of causing further upset.
Dr Leunig's forthcoming work is unlikely to spark a similar furore: he is publishing a report on the performance of the railways in the 19th and 20th centuries and another on mobility of apprentices in the 17th century.