He also denied that Mr Farage shared any of Mr Galloway's views on Israel – also dismissing any suggestion that the two were now friends.
Lawyer Mr Reid said: "The real situation is they have no more in common than when they first started – bar an interest in coming out of Europe.
"They have nothing in common when it comes to Israel, definitely not."
He said the decision to have a picture together was "stupid".
"It was not thought through," he added. "I advise [Mr Farage] and he did not tell me about it. No one came to me and said: 'Would you do this?'
"I would have said 'no'.
"I sent Nigel a note afterwards – I don't think he disagreed [with me]."
Mr Reid, a former deputy chairman of Hendon Conservatives and an anti-Europe campaigner, said he would back a hypothetical alliance between Tory MP Boris Johnson, who has openly backed Brexit, and Mr Farage.
"If we get out of Europe, hopefully there will be a new centre party," he said. "Both of them together would be a very good combination."
