|Newt Gingrich said in a statement that he is still a candidate, despite the resignations [EPA]
The entire top echelon of Republican Newt Gingrich's presidential campaign team has resigned in a devastating blow to the US candidate's 2012 election hopes.
Rick Tyler, who quit as Gingrich's spokesman on Thursday, cited "a difference of opinion on how to move forward" as the reason he, campaign manager Rob Johnson, senior strategist Dave Carney and others left the campaign.
"The professional team came to the realisation that the direction of the campaign they sought and Newt's vision for the campaign were incompatible," Carney told American television network NBC on Thursday.
Gingrich said in a statement that he is still a candidate.
"I am committed to running the substantive, solutions-oriented campaign I set out to run earlier this spring," he said. "The campaign begins anew Sunday in Los Angeles."
However, the mass exodus from Gingrich's campaign - which has sputtered from the beginning - could scare off would-be financial contributors and other supporters.
"It's a bombshell," said Darrell West, a political analyst with the Brookings Institution. "It's devastating for Gingrich to have his entire senior political leadership resign en masse in this way.
"And even more disturbing is the fact that their reason is that they had disagreements over the future vision, strategy and tactics of the campaign. So when you have that type of disarray at the very top of your campaign or organisation, it's devastating."
Texas Governor Rick Perry, considering a late entry into the 2012 contest, could benefit from the developments, since Carney and Johnson are former Perry aides who left his side when he had earlier ruled out a race.
The list of resigning officials included leaders of Gingrich's operations in the early voting states of New Hampshire, Iowa and South Carolina as well as Gingrich's home state of Georgia.
In another blow, Sonny Perdue, a former Georgia governor who had been Gingrich's national campaign co-chairman, announced he had joined the presidential campaign of former Minnesota Governor Tim Pawlenty.
Gingrich, who ushered in the Republican revolution while he was the leader of the US House of Representatives from 1995 to 1999, announced on May 11 that he would seek the Republican nomination for US president.
But within days, he ran afoul of Republican leaders by criticising Representative Paul Ryan's proposal to reform Medicare. Then it was disclosed he had carried as much as $500,000 in debt to jewelry company Tiffany from 2005 to 2006.
Most recently, with the campaign trying to build all-important momentum in its first month, Gingrich disappeared for a week to take a cruise with his wife, Callista, to the Greek Islands - another apparent bone of contention among campaign staff.
As speaker of the House, Gingrich was best known for helping draft the "Contract with America," 10 socially-conservative items the new Republican-dominated House put to a vote within the first 100 days in office.
But Gingrich has long been a polarising figure in US politics.
His tenure is equally remembered for the infamous four-week government shutdown in 1995 and 1996, when all but essential government personnel were furloughed after a budget fight led by Gingrich and then President Bill Clinton.
The Republican race to find a candidate to challenge President Barack Obama has been slow to start and Republicans complain the candidates so far are not strong enough.
Obama retains a big lead over possible Republican rivals in the 2012 election despite anxiety about the economy and the country's future, according to a Reuters/Ipsos poll this week.