The floors occupied by these families in the multi-storied buildings in the complex were declared unauthorised by the court.
In the letter, Mr Deora has asked Sonia Gandhi to persuade Maharashtra Chief Minister Prithviraj Chavan to find a legal solution to avoid the demolition.
The minister has written that these families are victims of the nexus between builders and the Municipal Corporation.
This is a classic case where builders have duped house owners in collusion with the authorities, Mr Deora has written.
The families are supposed to vacate their flats by Monday, as the Supreme Court recently refused to grant them relief.