US President Barack Obama on Friday makes his first major post-election intervention in a fast building showdown with Republicans over a tax and spending quagmire that could spark a recession. Obama was to lay out his high pressure gambit in a statement from the White House on the so called \"fiscal cliff\" -- $600 billion worth of automatic budget cuts and expiring tax cuts due to come into force on January 1. The president and Republicans are groping towards a deal which could avert catastrophic economic damage in the changed political atmosphere following the president\'s re-election triumph on Tuesday. But they appear fundamentally divided on principle. Obama won a second term by campaigning on a platform of rising taxes on the richest Americans but Republicans rule out tax increases and want cuts to cherished social programs. Obama was not expected to lay out significantly new proposals, but his statement, at 1 pm (1700 GMT) from the White House, will be crucial to setting the tone of intense, looming negotiations.Republican House Speaker John Boehner, who will be Obama\'s ultimate opposite number in fiscal cliff negotiations, said Friday that the onus for averting the crisis lay with the president. \"This is an opportunity for the president to lead,\" Speaker of the House John Boehner told reporters 90 minutes before Obama was due to speak. \"This is his moment to engage the Congress and work towards a solution that can pass both chambers.\" \"I\'m proposing we avert the fiscal cliff together in a manner that ensures that 2013 is finally the year that our government comes to grips with the major problems facing us,\" Boehner said. But he reiterated his opposition to raising taxes on the wealthy as a way to slice into America\'s growing debt, saying \"raising tax rates will slow down our ability to create the jobs that everyone says they want.\" Boehner pointed to \"special interest loopholes in the tax code, both corporate and personal,\" as well as deductions that could be eliminated as a way to raise revenue while not deterring investment. Boehner has made clear that a comprehensive long-term plan for debt reduction was unlikely in the next seven weeks of the outgoing \"lame duck\" Congress, but that a short-term compromise could be achieved. That was a challenge to Obama, who has previously opposed calls for a short-term fix that would just mean \"kicking the can down the road.\" The House leader has tried to appear conciliatory given Obama\'s cruise to victory in the election over Republican Mitt Romney, which replenished the president\'s political capital. But Boehner sits atop a restive coalition of ultra-conservative Republican lawmakers and faces a tough sell in any deal that eventually includes any kind of tax hikes -- or \"increased revenues\" in government parlance. The non partisan Congressional Budget Office warned this week that if the fiscal cliff is not averted, unemployment would rise to 9.1 percent from the current 7.9 percent by the end of next year.