SINGAPORE/LONDON (Reuters) -From ho-hum debt auctions to plunging long-term bond prices, investors are sending a clear message to governments that in the current climate of uncertainty they need to pay more to borrow for decades ahead. Yields of government bonds with the longest maturities have risen sharply not just in the United States, where the chaotic first months of Donald Trump's second term in the White House are causing investors to demand better returns on their bond holdings, but also in Japan and Britain. Multi-billion dollar government bond sales, which used to be a seamless process for big economies, are becoming the arena for bond vigilantes questioning government profligacy and inflation outlooks.