Questions about Miss Vorderman's association with Firstplus date back to 2001 when in the Commons MPs condemned commercials for firms offering consolidation loans.
A spokesman for Firstplus said: 'We know that Carol gives customers the feeling that Firstplus can provide the best financial deal to restructure debts quickly, easily and responsibly. That is a promise we do our best to live up to.'
Miss Vorderman's agent, John Miles, said: 'Carol has been working with Firstplus for nine years. She is very happy with the way they do business. They are an excellent company.'