John McCain gave interviews to all three network television news shows yesterday morning as he sought to suck some of the oxygen from Barack Obama's headline-grabbing world tour.

The Republican presidential candidate was speaking at the start of a week-long tour of battleground states.

Although his focus will be on domestic issues when he visits key swing states such as Ohio and Pennsylvania, he is taking every opportunity to accuse Mr Obama of being inexperienced and lacking judgment when it comes to foreign policy.

Mr McCain and his aides know how difficult the election campaign will be against Mr Obama, who has raised far more money, receives more media coverage and is not tarnished by the unpopular Republican brand.

A news coverage survey reported that, since last month, the three news networks — with a combined audience of 20 million — spent about 114 minutes covering Mr Obama and only 48 minutes reporting on Mr McCain.

Yet the two remain almost tied in the polls, due in part to the enormous advantage that Mr McCain has on the issues of foreign policy and leadership in the world.

A survey last week found that 76 per cent of Americans believed that the Republican would make a good commander-in-chief, to 48 per cent for Mr Obama.

Strategists for Mr McCain said that his best chance for victory would be to make the election a referendum on the vulnerabilities of Mr Obama, so the uneven media attention was not necessarily a disadvantage.

Already they have sought to exploit doubts that voters have about the ability of the Democrat to confront America's enemies abroad.

They will be watching his every move in the hope that he will stumble during his foreign trip.

Every day for the past week Mr McCain has said that Mr Obama opposed the surge of additional US troops to Iraq last year, a strategy that has led to reduced violence and talk of withdrawing troops.

“He should admit he was wrong about the surge,” Mr McCain said. He claimed that the military would have pulled out in defeat this year if the US had followed the Democrat's advice.

When Mr McCain made a trip to Europe and the Middle East in May, only a few journalists followed him and it received scant coverage. Mr Obama has taken along more than 40 journalists — none from the foreign press — and three prime-time news anchors.

Asked if the media situation was unfair, Mr McCain laughed and said: “It is what it is,” adding that the American people could decide for themselves. Privately his aides are less sanguine, believing that the news coverage is tilted in favour of Mr Obama.

Suspicions of media bias were fuelled by reports last night that The New York Times — viewed by Republicans as a bastion of liberalism — had rejected an opinion piece written by the Arizona senator, a week after it published one by Mr Obama.

The greatest vulnerability for Mr McCain remains the economy. He was not helped last week by one of his chief economic advisers, the former Texas senator Phil Gramm, who said that Americans had become a “nation of whiners” in a “mental recession”. He resigned as campaign co-chairman for Mr McCain.

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