Rudy Giuliani, the former New York mayor, was rushed to hospital after falling ill during a campaign stop in Missouri yesterday, just as the latest polls showed his lead in the race for the Republican presidential nomination had completely evaporated.

The former frontrunner had experienced flu-like symptoms which had worsened as the day progressed, according to Katie Levinson, his campaign spokeswoman. Shortly after the plane took off from Chesterfield, Missouri, for New York, Mr Giuliani’s condition deteriorated to the point that a decision was made to abort the flight, she said.

“The symptoms worsened as the day wore on and shortly after taking off from Chesterfield, Missouri, for New York the mayor became uncomfortable enough that our plane returned to the airport in Chesterfield,” Ms Levinson explained.

“To be on the safe side, the mayor consulted with his personal physician in New York and made the decision to go to the Barnes Jewish Hospital in St. Louis for routine tests.”

No further news has yet emerged as to the condition of Mr Giuliani, who successfully battled prostate cancer after being diagnosed six years ago.

His campaign, however, is looking in increasingly poor health. The one-time favourite has plummeted 13 points since November and is now tied with Mitt Romney nationally in the race for the candidacy, according to a new NBC News/Wall Street Journal poll released yesterday.

Support for Mr Giuliani has dwindled from a hefty 33 per cent in last month’s survey to just 20 per cent, wiping out his lead over the former Massachusetts governor.

Mike Huckabee, the former Arkansas governor and Southern Baptist minister who is emerging as the darling of the Christian right, was in third place with 17 per cent support among Republican primary voters. He was followed by John McCain, the moderate senator from Arizona, at 14 per cent and Fred Thompson, the former Tennessee senator and star of US TV series Law and Order, at 11 per cent, the poll found.

Mr Giuliani had been the clear leader in all previous NBC/Journal polls but his campaign has faltered in recent months as media scrutiny intensified.

His relationship with Bernard Kerik, the former New York City Police Commissioner recently indicted on corruption charges, and with donor Paul Singer, who operates a so-called vulture fund which makes profit out of the debt of poor countries, have come in for particular attention.

The campaign also did not put much emphasis on Iowa and New Hampshire, small but crucial states where candidates next month face the first contests in the process of determining who will be the Republican and Democratic candidates in the November 2008 presidential election.

According to the poll, just 37 per cent now view Mr Giuliani favourably, compared with an equal 37 per cent who have a negative impression of him. In March, 58 per cent viewed Giuliani favourably versus only 14 per cent who saw him in a negative light, NBC reported.

Among Democrats, Hillary Clinton held her national lead in the poll, commanding the support of 45 per cent of Democratic primary voters. She retains a substantial margin over Barack Obama despite his increased momentum in recent weeks, while John Edwards, the former North Carolina senator and 2004 vice-presidential candidate, commands 13 per cent. No other Democratic candidate received more than 4 per cent, NBC reported.

In Iowa, meanwhile, support for Mr Giuliani is virtually non-existent. A new Washington Post-ABC News Iowa poll, found Mr Huckabee has the support of 35 per cent of likely Republican caucus-goers, with Mr Romney the nearest challenger with 27 per cent. For the first time in Post-ABC Iowa polling, no other candidate registered in double digits, the newspaper said.

Mr Huckabee’s backing in Iowa has quadrupled since July, driven by a leap in support from women who describe themselves as evangelicals, the Post said.

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