Wonga, which offers instant short-term loans of up to £1,000 with APRs of sometimes more than 4,000%, has agreed to sponsor the primetime entertainment programme when it returns to ITV1 this year. The deal is thought to be worth up to £1m.
However, Stella Creasy MP wants to see tougher regulation for services such as Wonga, which she has branded "legal loan sharks".
Wonga, which has also been criticised by the Office of Fair Trading over its debt collection methods, will use the sponsorship of Simon Cowell's Red or Black? to promote its offer of "straight talking money".
But Creasy tweeted show presenters Anthony McPartlin and Declan Donnelly today, saying: "Hey @antanddec can I persuade you not 2 promote legal loan sharks by saying no 2 Wonga sponsoring red or black?"
She also urged her more than 17,000 followers to email the TV stars' agent and send a message that "Wonga is wronga until there's caps on the cost of credit".
In a statement, a spokesperson for Ant & Dec said: "Ant & Dec are the presenters of Red or Black?. As presenters, the sponsorship of the series has nothing to do with them. They are not executive producers of Red or Black?."
Wonga said that its sponsorship of Red or Black? represents a "great way" for the firm to raise awareness of its offer of "straight talking money".
Darryl Bowman, the head of marketing at Wonga.com, said: "We're pleased to be supporting such a big show which, like our service, has been a hit with a mainstream audience from the beginning.
"We're excited about bringing our 'straight talking' take to Saturday nights. This sponsorship will be another great way for us to continue raising awareness of our brand and services."
An ITV spokeswoman added: "Wonga is a well known brand and the sponsorship of Red or Black? is fully compliant with Ofcom regulations."
The exact value of Wonga's sponsorship deal across broadcast, online and mobile is not known, but pizza company Domino's paid around £1m to sponsor last year's series of Red or Black?.
Wonga is no stranger to controversy with its advertising. The Football League recently ended a deal involving the lending service sponsoring its websites after a protest campaign from users.
The Advertising Standards Authority also previously considered 82 complaints about targeted marketing campaigns by the company, but opted to pursue no further action.
Red or Black? will return this year with a revamped format following complaints by the gambling commission that the chance-orientated gameshow encouraged gambling.
Instead of a £1m nightly jackpot won via a giant roulette wheel, the programme will now offer a £500,000 prize with contestants expected to use their "skill and judgement" to scoop the cash.
