The problems afflicting John McCain’s presidential campaign were symbolised yesterday by a picture of him with a worrying “nickel-sized” dark spot on his forehead.

An aide swiftly dismissed the photograph on the popular Drudge Report website as “a minor blemish”. The implication, however, was that it may be evidence of something more serious, possibly a return of the skin cancer for which he had surgery in 2000.

There are similar questions about other troubles the Republican Senator has encountered in the past week: are these merely surface blemishes — or do they go deeper? There is already speculation — hotly denied — that his campaign is planning a relaunch next week.

On Monday his campaign published figures showing that he had raised $12.5 million (£6.2 million) in the first quarter of this year, placing him third — behind Mitt Romney and Rudy Giuliani — in the Republican “money primary”.

On the same day Mr McCain was in Baghdad where he toured a local market and said that his ability to walk freely through the city showed that “things are better and there are encouraging signs”.

Traders from that same market later contradicted his account, saying that they had told the delegation about the mortal danger they faced. The security surrounding Mr McCain’s visit — where he was protected by helicopters, armed guards, snipers and a bullet-proof vest — was, they said, “abnormal”.

On Tuesday there were claims that he had considered defecting from the Republicans in 2001 and that aides had later approached John Kerry, the Democratic presidential candidate in 2004, to suggest he could join the ticket as the vice-presidential nominee.

Mr McCain’s campaign expressed confidence yesterday that it had successfully rebutted the allegations with a detailed account which, “at worst”, suggests that his adviser John Weaver had “got ahead of himself in examining options” and that the Senator had done nothing to encourage him.

The claims were disseminated widely and discussed on right-wing websites. Many Republican activists have never trusted Mr McCain. Indeed, some are relishing the plight of a man who joined forces with the ultra-liberal Democratic Senator Russ Feingold to pioneer campaign finance reforms and is now struggling to raise money himself.

A source close to Mr McCain conceded yesterday that the funding shortfall “had left us with some egg on our face” but said that steps were already being taken to address the problem.

“We thought we would not have to do events and move John around the country — that the money would just come to us. But Republican donors have been conditioned not to sign cheques until they have seen the candidate in their town and effectively asked personally by him to give money,” said the source.

The campaign rejects suggestions that Mr McCain is being forced to “relaunch” his faltering candidacy. It confirmed, however, that he would be delivering a major speech next week on Iraq, followed by two more on the economy and his domestic policy agenda, before announcing his run for the White House formally with a tour through the early primary states and finishing at his base in Arizona at the end of the month.

Opinion polls consistently show Mr McCain in second place behind Mr Giuliani in the race for the 2008 Republican nomination. His popularity appears to have diminished among moderates and independents as he seeks to impose himself as the “establishment candidate” on a party that remains suspicious of him.

A key aide said yesterday that the Senator was now kicking off his political rust and beginning to recreate the excitement of his maverick “straight-talk” campaign in 2000. “If by September, things have continued to go the wrong way, then yes, people might say the first signs of malaise were back in March.

“My view is that this is not a long-term problem, there are going to be a whole lot more ups and downs along the way but John has good staff and good operations in the field. He should be okay.”

Times Recommends

• The Japanese Prime Minister is doomed: or is he?
• Brighton company 'involved in cyber attack'
• The art of survival: it's all in the mind