Newt Gingrich's $500 cheque bounces for Utah primary
A $500 (£314) cheque issued by the cash-strapped campaign of Republican candidate Newt Gingrich bounced, it has emerged.
Election officials in Utah told US media they contacted the Gingrich campaign over the unpaid filing fee for the state's primary in June.
Mr Gingrich has vowed to stay in the contest following Tuesday's exit of Republican rival Rick Santorum.
But front-runner Mitt Romney is expected to wrap up the race by June.
Utah election officials say the cheque bounced on 27 March. The fee must be paid by 20 April if Mr Gingrich is to qualify for the ballot.
Last conservative standing?
Following Mr Santorum's departure on Tuesday, Mr Gingrich appealed for donations online.
"It is now a 2 person race," the former House Speaker tweeted , calling himself "the last conservative standing".
Mr Gingrich's campaign, which cut a third of its staff in March, told ABC News on Tuesday it was $4.5m in debt.
It was reported last month that the Gingrich campaign's latest fundraising tactic was to charge people $50 to have their photo taken with the candidate.
Texas Congressman Ron Paul has also said he would not drop out of the race, although he and Mr Gingrich lag far behind.
Mr Romney is expected to gather the 1,144 delegates needed to clinch the party's nomination by early June.