HATFIELD, Penn. — President Barack Obama will take the rhetorical gloves off Friday, using a speech in suburban Philadelphia to hammer Republicans as beholden to wealthy interests at the expense of the middle class.

"The president will be clear that the House needs to follow the Senate's lead and act so that 98% of Americans don’t see their taxes go up at the end of the year," a White House official told reporters on the condition of anonymity. The speech is designed to escalate pressure on Republicans, who have been resisting Obama's demands.

"And he will call on Congressional Republicans to stop holding the middle-class tax cuts hostage simply because they refuse to let tax rates go up for the wealthiest Americans."

In recent weeks the White House warned Congress against holding the tax cuts hostage, but the new focus specifically on Republicans represents an escalation in tone in the ongoing fiscal cliff negotiations, which appear to have stalemated.

In his remarks at The Rodon Group, a domestic plastics manufacturing company, Obama will also reiterate his commitment that in any fiscal cliff agreement, the wealthy will pay higher tax rates than they do now — something most Republicans are dead-set against.

Obama has pledged to take his case to the people, in campaign-style events across the country if necessary, to pressure Congress — and now specifically Republicans — to reach a deal.