Fines for "unauthorised development" such as the demolition of listed buildings are being increased to £10 million for convictions on indictment and from £1,000 to £1,500 for summary convictions, under the new Planning Bill.
Mr Dempsey believes the present maximum fine of £1 million for convictions on indictment is an insufficient deterrent, especially in city-centre areas where property values are high, although no such fine has been imposed on any developer so far.
The Bill introduces a new planning enforcement regime to remedy what is seen as a serious deficiency in the system.
In future, local authorities will be obliged to follow up "genuine complaints" about breaches of planning control within a given time-frame.
They will also be entitled to retain fines imposed by the courts for planning offences and to refuse planning permission - subject to the consent of the High Court - to any developer who has "seriously failed" to comply with the terms of a previous permission.
Local authorities will also have an obligation to take housing estates in charge when they are finished and even when they are not, in cases where no enforcement action has been taken against a defaulting developer.
There will also be heavy financial penalties for applications to retain an unauthorised development.
Furthermore, a court will no longer be able to take into account the lodging by a developer of an application for retention when enforcement action is being taken.
