G7 leaders on Friday warned that a UK exit from the EU could have disastrous economic consequences. The leaders issued a declaration during the summit in Japan that an exit poses a serious risk to growth. 

They say it would reverse the trend toward greater global trade and investment, and the jobs the UK creates. The comments highlight growing international alarm over the possibility of a so-called “Brexit.”

UK voters are preparing for a June 23 referendum to decide whether to leave the 28-country bloc. Prime Minister David Cameron has been campaigning for Britain to stay in, with recent British polls suggesting a widening lead for supporters of continued EU membership. 

But the leave campaign is offering up stiff competition, with a number of high-profile supporters such as former London mayor Boris Johnson.