* Speech to focus on middle-class jobs
* Could face stiff Republican opposition
President Barack Obama will describe his plan for spurring the economy in his State of the Union address on Tuesday, offering proposals for investments in infrastructure, manufacturing, clean energy and education, a senior administration official said on Saturday.
In the annual presidential address to Congress, Obama plans to show he has not lost sight of the economic woes of middle-class Americans - issues that dominated the 2012 election campaign but have been overshadowed recently by efforts to cut the deficit, overhaul immigration laws and curb gun violence.
"The potential success of his second term is hugely dependent on the rate at which the economy grows," said Ruy Teixeira, a political scientist with the liberal-leaning Center for American Progress.
"There's no problem the Democrats have that can't be solved with faster growth. Conversely, there's not much they'll be able to do if growth stays slow."
Obama previewed his economic growth plan in a speech to House of Representatives Democrats this week, telling them he would stress the importance of education, development of clean energy, and infrastructure.
There were no details on the new initiatives for infrastructure, manufacturing, clean energy and education, elements first reported by the New York Times.
But any new spending will face tough opposition from Republicans in Congress who are focused on cutting spending and reducing the deficit.
Obama has urged Congress to take steps to postpone harsh government spending cuts slated to take effect on March 1, and the White House took pains on Friday to describe how the cuts would affect ordinary Americans' lives.
Obama has said he is willing to cut a "big deal" with Republicans to trim spending on the Medicare and Social Security programs for the elderly, but has insisted in ending long-standing tax breaks for oil companies, private equity firms and corporate jet owners to create more revenue for government.