Pay attention at the back
BBC News, July 8 2005: ID cards ‘wouldn’t stop attacks’
Asked by BBC Radio 4’s Today programme if ID cards could have prevented Thursday’s atrocity, Mr Clarke said: “I doubt it would have made a difference.
“I’ve never argued … that ID cards would prevent any particular act.
Guardian, 10 January 2006: Labour MPs oppose partial ban on smoking but back ID cards
Among Labour MPs there was strong support for… introducing identity cards…
“I may have been an opponent but 7/7 has had an influence on my opinion,” said one longstanding MP, Harry Cohen.
Posted on January 10th, 2006 at 8:43am under Affronts to democracy, ID cards, T.W.A.T., The home front, UK politics

Of course, Charles Clarke did suggest that control orders could have stopped Madrid. Now, unless these control orders would be broad sweeps of suspect populations, that must have meant that the Spanish government was lying when they blamed ETA.
Not surprisingly, I did not receive a response to my letter.