LONDON (Reuters) - London's standing as Europe's leading destination for tech start-ups is at risk if the British government does not clarify how it plans to keep the best technical talent, entrepreneurs and investors have warned.<div><a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=39QVYSffVbo:cI_TJmPu2Og:yIl2AUoC8zA"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?d=yIl2AUoC8zA" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=39QVYSffVbo:cI_TJmPu2Og:V_sGLiPBpWU"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=39QVYSffVbo:cI_TJmPu2Og:V_sGLiPBpWU" border="0" /></a> <a href="http://feeds.reuters.com/~ff/reuters/technologyNews?a=39QVYSffVbo:cI_TJmPu2Og:-BTjWOF_DHI"><img src="http://feeds.feedburner.com/~ff/reuters/technologyNews?i=39QVYSffVbo:cI_TJmPu2Og:-BTjWOF_DHI" border="0" /></a></div><img src="http://feeds.feedburner.com/~r/reuters/technologyNews/~4/39QVYSffVbo" height="1" width="1" alt="" />