A U.S. federal judge on Tuesday ruled against the Obama administration's six-month ban on deepwater drilling, saying the move will cause "immediate and irreparable harm to businesses" along the Gulf Coast.

A supply vessel passes through oil floating near the site of the Deepwater Horizon oil spill in the Gulf of Mexico off Louisiana on May 31.[chinanews.com]

The ruling was handed down by U.S. District Judge Martin Feldman, one day after hearing arguments in the case filed by Louisiana-based Hornbeck Offshore Services LLC and joined by more than a dozen oil service companies, in a federal court in New Orleans.

The White House plans to appeal Feldman's decision to issue a restraining order blocking the government from enforcing its ban, a White House official said.

The six-month moratorium, imposed by the Department of Interior in the aftermath of the massive oil spill in the Gulf of Mexico, banned drilling for oil and gas in water depths of at least 500 feet (about 152 meters), idling 33 deepwater rigs operating in the Gulf of Mexico.

The White House said the move is necessary to allow federal regulators "time to step back and investigate both the root causes of the Deepwater Horizon disaster and to implement additional safety measures to ensure that we don't fall victim to another disastrous oil spill."

But the plaintiffs' lawyers argued that the ban was arbitrarily imposed. They also said the move could be more economically devastating than the spill itself.

Feldman said in his ruling that the Interior Department assumed that because one rig failed, all companies and rigs doing deepwater drilling pose an imminent danger.