The U.S President Barack Obama yesterday called on Congress to approve a one year extension of Bush-era tax cuts for people making less than 250,000 dollars per year, a proposal that has been rejected by congressional Republicans and likely Republican Party Presidential nominee Mitt omney.Obama's challenge to Congress came as Republicans seek an extension of all cuts for middle and upper-income Americans made under Obama's predecessor George W. Bush.As Obama campaigns for re-election, he is emphasizing what he says are the benefits of his policies and fairness for the middle class – contrasting his proposals with those of former Massachusetts Governor Mitt Romney.In a compromise with congressional Republicans in 2010, Obama agreed to a two year extension of Bush-era tax cuts, but said he would not agree to another extension. If Congress does not act before the end of this year, rates for all Americans will increase. Economists warn of a potential double punch to the economy from this and automatic mandatory spending cuts beginning at the same time.Obama will visit the Midwestern state of Iowa today to deliver remarks at the home of a middle class family that would face a substantial tax increase, if Congress does not act by the end of the year.