Councillors this week backed a motion to approach the Welsh Assembly Government to introduce a "clause of protection".
The council said it is turning down what it thinks are unsuitable developments only for inspectors to approve them on appeal because there is no LDP in place.
The council submitted the new-style plan to the assembly in 2005 but it was rejected because of a lack of evidence on housing. Its previous plan ran out last December and a final LDP is not due for completion until 2012.
Deputy leader Phil Edwards told Planning that the council has lost nine cases on appeal in the past year. He described the current situation as "chaotic".
"There is nothing preventing developers from building on greenfield sites," he said. "We want an end to it."
Edwards argued that the council has also lost land allocated for employment space, which would lead to unsustainable developments. He added: "Two of the nine schemes represent hundreds of homes. However, there is no infrastructure such as services and schools to support them."
A Welsh Assembly spokeswoman said Conwy started work on the LDP ahead of guidance on preparing the plans. The council was warned that the LDP would be found unsound. It decided to reconsult but it has not yet done so.