Our planning system is in chaos – or at least there is a serious risk that it will be if the House of Lords upholds the High Court judgment in the Alconbury case when the Government's appeal is heard next month. That is not good news when you consider that the property sector in the UK accounts for nearly 10 per cent of the UK's gross domestic product.

As a result of the judgment, the Secretary of State's role in the planning process, as both policymaker and decision-taker, has been held to be incompatible with the right to a fair hearing under the European Convention on Human Rights and he faces the prospect of having to divest himself of his decision-making powers. It is not just the largest projects, such as Terminal 5, that have been thrown into confusion by this decision. All developments requiring compulsory purchase or highway closure orders to be confirmed by the Secretary of State will be affected by the court's decision. And there are almost certainly further planning cases to follow as a result of the Human Rights Act. It is only a matter of time, for example, before a council is challenged for granting itself planning permission on land which it owns.

There has already been a good deal of speculation within the development industry and among planning specialists from various disciplines regarding the most appropriate system to replace the Secretary of State's role. Some have suggested a truly independent planning inspectorate, freed from the shackles of political influence, while others are championing a planning and environmental division of the High Court. The ground has been laid for a healthy debate.

What has been noticeable for its absence thus far, however, is a proper response from the Government itself. Apart from one or two anodyne replies to parliamentary questions, to the effect of "business as usual" pending any appeal, there has been a spectacular silence from the Department of the Environment, Transport and the Regions. The Government has given no indication that it will be ready to move swiftly if the High Court's decision is upheld – and swiftly it will have to move if important developments are not to be frustrated by the delay of introducing a new regime.

The lack of any comment from the Government at this stage is not surprising – it certainly would not wish to prejudice its chances on appeal by acknowledging that the game is already up. There is, however, a legitimately held assumption within the industry that the Government is preparing proposals that it will be ready to disclose immediately upon it becoming clear that changes are required. Those proposals will need to be considered, clear and workable. Most importantly, they will need to address the wide range of practical problems with which those of us closely involved in the planning process are now having to grapple as a result of the Alconbury decision and the Human Rights Act generally. As such, the proposals will need to anticipate potential problems that have not yet been brought before the courts.

And herein lies the message. There is a huge body of external experience upon which the Government is able to draw when formulating any new system. Historically, governments have not been slow to use that experience when consulting on planning matters. Specialist planning lawyers are among those who have the most to offer to this current debate and there is much of value which they are willing and ready to contribute to the structuring of a new system. Like everyone else involved in the planning process, however, they are waiting for confirmation from the Government that, if the High Court decision is upheld, proposed amendments to the system will be issued for urgent debate and a timetable for change will be triggered.

Without such an early assurance, the development industry's faith in the planning system will certainly be further diminished.

Michael Gallimore is head of planning at Lovells.