Republican presidential candidate Donald Trump - looking to turn the page on his troubled bid for the White House - unveiled his plans to spur economic growth, which include sweeping tax cuts, slashing federal regulations and reviving a controversial oil pipeline project.

Speaking at a closed-door gathering at the Detroit Economic Club Trump said he wants to consolidate seven tax brackets into three - 33 percent, 25 percent and 12 percent, while slashing the corporate tax rate from 35 percent to 15 percent.

This, he said would, would bring American businesses that have relocated abroad back to the US.

Trump is trying to recover from what has been the worst stretch of his unlikely presidential bid.

His poll numbers plunged over the past two weeks after a series of mishaps, none more damaging than his misbegotten verbal fight with the parents of a US soldier who died defending his unit in Iraq.

National opinion polls showed Democrat Hillary Clinton opening up an 8-15 point lead in the aftermath of Trumps bungling. Clinton, incidentally, will be in Detroit on Thursday to give her own economic speech.

Despite reading from a script at a closed-door gathering Trump was, nonetheless, repeatedly interrupted by protesters. In all 14 people jumped up to interrupt, many at one or two-minute intervals, suggesting the disruptions were a coordinated attempt to rattle the tempestuous candidate.

But others in the crowd cheered Trump, and he kept his cool.

A populist message

His remarks appeared to be aimed at both the affluent business community and the working class, in particular those who have suffered from the decline in US manufacturing jobs in economically depressed cities such as Detroit.

He vowed to impose a temporary moratorium on new federal regulations and to establish new provisions to help working parents deal with childcare costs, a subject that has generally been anathema to Republican orthodoxy.

His plan to slash taxes reflected traditional Republican thinking that lower taxes will generate economic growth and create jobs.

Trump renewed his attacks on free trade, saying he would rewrite the landmark NAFTA trade deal that Clinton's husband, then-President Bill Clinton, signed in 1994. The pact link the economies of the United States, Mexico and Canada.

He likewise reaffirmed his commitment to withdrawing the US from the Trans Pacific Partnership - a massive trade deal backed by President Barack Obama.

He also promised to bring back the highly controversial Keystone oil pipeline project that Obama turned down. It would cut through the center of the country, from Canada-to-Texas.

"We now begin a great national conversation about economic renewal for America," he said. "It's a conversation about how to make America great again for everyone...especially for those who have the very least."

bik/bw (Reuters, AP, AFP)