The head of the US central bank, Ben Bernanke, has warned that fiscal stimulus alone will not be enough to promote a lasting US economic recovery.Making as speech at the London School of Economics the Federal Reserve Chairman said further steps may be needed to bailout US banks. As he spoke Europe’s stock markets slid for the fifth day running. Investors are increasingly worried about how bad company results for fourth-quarter are going to be. Banks are seen as particularly vulnerable and were big losers along with the insurance sector and mining companies. The pound and the euro are both lower against the dollar but oil jumped after Saudi Arabia said it had removed 1.7 million barrels per day of crude oil from the world market since last summer.