A judge in the US has ruled that Vice-President Dick Cheney does not have to release details of meetings with oil executives to the investigative arm of Congress.

The General Accounting Office sued the White House for names of people consulted over energy policy as part of its remit to ensure the government's accountability.

The lawsuit into the energy policy was filed during the Enron scandal

The Bush administration welcomed the decision permitting confidentiality as a way for officials to continue to receive "unvarnished advice".

But opponents said the dismissal of the unprecedented lawsuit could mean a lack of scrutiny of and accountability for government decisions.

The GAO - the investigative arm of Congress - filed its action in February seeking the names of oil industry officials consulted by Mr Cheney who headed a task force to develop a new energy policy.

The suit sought to discover what role executives from Enron had played before the announcement of the plan, which called for more oil and gas drilling in the Arctic wildlife refuge and a possible revival of nuclear plants.

'No endorsement'

The White House acknowledged meetings between Mr Cheney and executives from Enron - which was a huge contributor to President Bush before it collapsed owing billions of dollars in an accounting scandal.

We believe it's important for good decision-making that the president receives unvarnished advice

White House spokeswoman Claire Buchan

But a federal judge agreed with the administration that in general contacts could be kept secret.

US District Judge John Bates noted that while the GAO had been asked to investigate the matter by elected representatives, there was no overall endorsement from the House or Senate for the inquiry.

Without that, the head of the GAO David Walker did not have the backing to ask the courts to intervene, he ruled.

"Such an excursion by the judiciary would be unprecedented and would fly in the face of the restricted role of the federal courts under the Constitution," the judge wrote.

Appeal considered

Mr Walker, who had argued that the GAO had the right to the documents as part of its congressional oversight of the executive branch, said in a statement: "We are very disappointed."

The new energy policy included more drilling in Arctic nature reserves

White House spokeswoman Claire Buchan welcomed the decision.

"We believe it's important for good decision-making that the president receives unvarnished advice," she said.

The GAO said it would decide whether to appeal after completing a review of the decision and consulting with Congressional leaders from both Mr Bush's Republican Party and the opposition Democrats.

'Near total immunity'

Correspondents say the judge's ruling that GAO inquiries had to be endorsed by Congress means that a president could be largely free from aggressive congressional oversight unless an opposition party controls the House or Senate.

Representative Henry Waxman of California - one of the two lawmakers who first asked for an investigation of the operations of the energy task force - said the ruling gave the White House "near total immunity from scrutiny".

Representative John Dingell of Michigan said it was unlikely that the incoming Congress, with Republican majorities in both houses, would vote to subpoena documents from a Republican administration.

A lawsuit from Judicial Watch which also seeks energy task force documents is still ongoing.

Tom Fitton, president of the legal watchdog, said he was confident his organisation would win its battle to have the Cheney documents revealed.