The Department for Transport (DfT) last week outlined plans for a 2,200m runway with a supporting passenger terminal. The development would see the destruction of the village of Sipson and loss of about 700 properties.
Airport operator BAA has been involved in drawing up the consultation and setting out the framework for the proposals. But lobby group HACAN said it believes that the government might be on thin ice legally as BAA is also a respondent.
A DfT spokeswoman explained that the aviation white paper of 2003 said BAA should be involved in preparing the consultation. "It wouldn't have been practical to do it without the airport operator," she argued.
The DfT will also hold a series of public exhibitions in the areas affected by expansion. However, Sipson will not be included because an appropriate venue could not be found, the department claimed. Instead, a shuttle bus will take residents to nearby West Drayton.
Stewart insisted that HACAN will hold alternative exhibitions, including one in Sipson, to "get across that there is one simple issue - most people will be getting more planes".
The consultation ends on 27 February. Steve Mayner of the 2M Group of affected local authorities said it has hired consultants to help it through the consultation. "Councils are not resourced to this level of expertise, especially in the time available," he said.
Future Heathrow campaign director Clive Soley maintained that Heathrow is the UK's gateway to the global economy and "failure to expand is not an option".
BAA chief executive Stephen Nelson also claimed that there would be no more noise overall from the airport and air quality would improve.
Prime minister Gordon Brown showed his support for expansion at the CBI conference this week.
"We have to respond to a clear business imperative. The UK as a world financial centre must be readily accessible from around the world," he argued. The government estimates economic benefits from expansion at around £5 billion.
Adding Capacity at Heathrow Airport - Consultation Document is available at PlanningResource.co.uk/doc.