The pound suffered during foreign exchange trading yesterday (November 10th) after ratings agency Fitch declared that the UK is most at risk of losing its AAA sovereign credit rating.Of the four sovereign debt issuers - the US, Germany, France and the UK - Britain was said to be most at risk of losing its AAA status because it has the largest budget deficit.The Financial Times reports that the pound dropped rapidly in the immediate wake of the announcement, but recovered some losses before the close of the trading day.Speaking at reporters' briefing in London, prime minister Gordon Brown sought to assuage fears over the UK's growing debt mountain."We have assured people that we're taking the necessary action to cut the deficit in half. Our debt levels are roughly the same when this crisis ends as America, as France, as Germany," he commented.Meanwhile, in an investor note seen by Bloomberg, Barclays Capital yesterday declared that the sell-off which followed the Fitch announcement created a buying opportunity for the pound.