 Such exchanges had happened before.Notable examples included Soviet spy Rudolf Abel for U2 pilot Gary Powers and Konon Molody (aka Gordon Lonsdale) for Greville Wynne, but British Prime Minister Harold Wilson's Labour Government was criticised by the opposition for agreeing to release Peter and Helen Kroger in exchange for Brooke.Opponents claimed it set a dangerous precedent, and was an example of blackmail rather than a fair exchange.