Lorraine was recently asked to film Christmas adverts for the supermarket chain. However, her boss feared that such a move would lead to more bad publicity for GMTV, which was fined £2 million by broadcasting regulator Ofcom in September for conning viewers with its premium-rate phone lines.
A source told the Sunday Mirror: "Clive made it very clear that she would not be allowed to do these adverts. The bosses are desperate to avoid any more scandals or unflattering headlines about conflicts of interest.
"Because GMTV is classed as a news channel, it's just not allowed for presenters to endorse commercial products."
A GMTV spokeswoman confirmed: "None of our presenters can do any kind of commercial endorsement... it's not just Lorraine."
Crouch took over as GMTV's managing director last month. Previous chief Paul Corley resigned over the phone-in row in July.