A Tennessee couple who experienced sudden unintended acceleration in a Lexus ES350 are among those expected to appear at a US Congressional hearing into the Toyota recalls later on Tuesday.

During three hearings scheduled over the next three days, lawmakers are expected to grill both Toyota and US safety regulators to see if they handled consumer complaints appropriately while another focus of attention will be whether the carmaker’s electronic throttle control system is the cause of sudden acceleration.

Toyota has repeatedly denied this is the case and the government safety body, the National Highway and Traffic Safety Agency (NHTSA) has also insisted none of its testing unearthed any defect.

The Tuesday morning (EST) hearing by a subcommittee of the House of Representatives Committee on Energy and Commerce, will see Toyota Motor Sales USA president Jim Lentz and US transportation secretary Ray LaHood testify.

Toyota president Akio Toyoda is scheduled to testify at the House Committee on Oversight and Government Reform to be held on Wednesday with LaHood and Toyota Motor North America president Yoshimi Inaba also attending.

Wednesday’s hearing is widely believed to be tougher for Toyota than Tuesday’s as some lawmakers such as ranking panel member Darrell Issa, a Republican from California, are expected to grill Toyota executives, Kyodo News reported.

US media have been increasing coverage, pointing to the possibility of defect cover-up and a slow response to complaints of American drivers over safety concerns.

Toyoda had originally declined to appear before US lawmakers, saying Inaba would be the best person to explain Toyota’s actions to US lawmakers and American drivers but last week changed his mind after the panel issued a formal invitation to him.

Many US media and lawmakers apparently took these earlier remarks as a sign of Toyoda’s reluctance to speak directly to US politicians and American consumers, the Japanese news agency said.

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