David Cameron to shed 'cast iron' pledge on Lisbon treaty Steve Bell cartoon: David Cameron to shed 'cast iron' pledge on Lisbon treaty Photograph: Steve Bell Illustration: Copyright © Steve Bell 2009Steve Bell cartoon: David Cameron to shed 'cast iron' pledge on Lisbon treaty Photograph: Steve Bell Illustration: Copyright © Steve Bell 2009Explore more on these topicsDavid CameronGuardian Opinion cartoon