HRT has scotched reports it will start the 2012 season with last year's car.
The BBC quoted a spokeswoman for the Spanish team as admitting to a "critical delay", but denied the recent staff and factory shakeups had overly affected development of the new single seater.
HRT's new car is highly anticipated, given the team's struggles since inception in 2010 with the uncompetitive Dallara design.
"Rumours that we will take part in the initial grands prix with the 2011 car are not true," said the spokeswoman.
"The target is to be at the second test with the new car."
The BBC said the team will be present at the opening test at Jerez early next month with the 2011 car.
The target is to be at the second test with the new car
The former Renault team, meanwhile - now called Lotus F1 - will be at Jerez with its new contender.
It will be launched two days earlier on the team website, before Kimi Raikkonen gives the car a brief track debut on 6 February -- the day before the official test kicks off.