Rishi Sunak will promise on Wednesday to do "whatever it takes", including a five-month extension of Britain's huge jobs rescue plan, to steer the economy through what he hopes will be the final months of Covid restrictions.Sunak has already racked up Britain's highest borrowing since World War Two and will turn to the bond markets again in his budget speech, saying the task of fixing the public finances will only begin once a recovery is in sight.Also Read | How citizen data led India’s Covid battle"We're using the full measure of our fiscal firepower to protect the jobs and livelihoods of the British people," Sunak will say, according to excerpts of his speech which is due to begin around 1230 GMT."First, we will continue doing whatever.