Washington: The White House on Thursday warned that latest round of a knock-down-drag-out budget battle on Capitol Hill could prompt another US government shut down.

Rival lawmakers in the Republican-dominated Congress have three weeks to reach a deal to fund the government beyond 1 October.

Conservative Republicans are refusing to back any plan that keeps funding for Planned Parenthood, a reproductive health organization that performs abortions.

‘If Republican leaders maintain their insistence on trying to pass a budget along party lines, then we are going to be headed for a shut down,’ White House spokesman Josh Earnest warned.

‘It’s clear to anybody that’s been paying attention over the last several months, that they don’t have the votes to pass a budget.’

Any shutdown would result in millions in lost wages and could prompt economic and financial turmoil at a time China’s slowdown has already roiled markets.

The last government shutdown happened in 2013, when Republicans sought to derail President Barack Obama’s health care reforms.

The two-week closure saw hundreds of thousands of federal employees sent home and national parks closed.

The US economy lost an estimated $24 billion.

Experts see a significant, and growing, chance that a deal is not reached.

Conservatives have reacted furiously to the emergence of clandestinely shot footage appearing to show Planned Parenthood staff discussing the sale of fetal tissue.

The organization said the tissue was destined for scientific research, with the consent of patients and talk of payment was only to cover costs.

But with the 2016 presidential race well underway, the row is politically turbo charged.

Republican Senator and presidential candidate Ted Cruz has called for an ‘investigation into potential criminal actions within the abortion industry.’

He has demanded an end to federal funding and denounced anti-Planned Parenthood ‘show votes’ that would allow conservatives to say they voted against the organization, while backing the budget.