Football Association boss Martin Glenn believes the plan to sell Wembley would be the right move as Gary Neville joined the band of opponents.
The proposed sale to Jacksonville Jaguars and Fulham owner Shahid Khan was the subject of a Digital, Culture, Media and Sport select committee hearing on Wednesday.
Former England and Manchester United defender Neville told MPs the idea was a "short-term play we'll regret forever" and that future financial benefits amounted to "a pittance in football".
Glenn said he was working with Government agency Sport England to "codify the guarantees" any new owner would have to give in terms of access to Wembley, retaining its name and keeping it fit for football.
Asked by reporters if this contract, which he said would be ready "within the month", could deter Khan, FA chief executive Glenn said: "No, we have been clear from the beginning that we would have to run an open process for the sale of such a high-profile asset."
Khan is the only interested party so far.
During the hearing, Glenn was flanked by Sports Minister Tracey Crouch and Sport England boss Nick Bitel, both of whom must consent to any sale as £161m of public money was used to build the stadium.
Glenn explained that Khan, who has made little secret of his desire to move his NFL franchise to London, had made offers for Wembley in the past.
However, the FA chief said this one, made last year, was the first that deserved consideration.
Source: Skysports