Washington believes that the ‘ special relationship ’ between Britain and the US is over , according to a secret briefing document seen by The Mail on Sunday . The memo for members of Congress states damningly that ‘ the UK may not be viewed as centrally relevant to the United States in all of the issues and relations considered a priority on the US agenda ’ . Dated April 2015 and drawn up to brief the Senate and House of Representatives on the impact of Britain ’ s General Election , the memo also warns that the UK faces turmoil if there is a hung parliament . Scroll down for video . The 'special relationship ' between Britain and the US was strong under Margaret Thatcher and Ronald Reagan . The document – prepared by the Congressional Research Service , an in-house intelligence body that gives confidential analysis to legislators – states that while Britain and the US are likely to ‘ remain key economic partners ’ , a ‘ reassessment of the special relationship may be in order… because its geopolitical setting has been changing ’ . The memo , edited by Derek E Mix , the CRS ’ s chief European affairs analyst , says that the development of organisations such as the G20 group of major economies has led to a decline in the ‘ influence and centrality of the relationship ’ . It also states that the UK ’ s continued importance to the US will hinge on the future success of the economy – and Chancellor George Osborne ’ s implementation of spending cuts . It reads : ‘ A significant degree of the UK ’ s international influence flows from the success and dynamism of the British economy , further raising the stakes on whether the UK can sustain stronger economic growth while continuing to pursue ambitious fiscal consolidation. ’ Prime Minister David Cameron and US President Barack Obama serve food during a Downing Street barbecue in May 2011 . When Cameron visited the White House in January , he insisted the President had said the special relationship was ‘ stronger than it has ever been ’ Winston Churchill first coined the phrase 'special relationship ' in a speech in 1944 . The ‘ special relationship ’ has been deployed by generations of politicians – most notably Ronald Reagan and Margaret Thatcher – to describe the close political , diplomatic , cultural , economic , military and historical relations between the two countries . It was first coined in a 1944 speech by Winston Churchill , when he said it was his ‘ deepest conviction that unless Britain and the United States are joined in a special relationship… another destructive war will come to pass ’ . Increasingly , however , the relationship has come to be seen as one-sided , with British Prime Ministers more keen to flag up the alliance than US Presidents . When David Cameron visited the White House in January , he insisted the President had said the special relationship was ‘ stronger than it has ever been ’ . The memo also expresses concern about a potential UK exit from the EU following an ‘ Out ’ vote in any referendum , saying : ‘ Both the positive and the negative aspects of a prospective life outside the EU are more difficult to foresee. ’ Explaining the significance of a hung parliament , the congressional document says it could result in a ‘ brief period of ambiguity ’ and ‘ constitutional uncertainty ’ .
Memo damningly states UK may no longer be 'centrally relevant ' to the US . Congressional Research Service , which gives confidential analysis , warns of turmoil if there is a hung parliament following general election . Comment: