FUNDAMENTAL design changes to Heathrow Terminal 5 mean crucial groundworks will not start until the end of this year, planners claimed last month.
Full planning consent is now unlikely to be granted until the end of the year following a redesign of the terminal and satellite building.
Tim Jurdon, head of aviation planning at the local authority, Hillingdon council, said: 'This is a major redesign and will take us at least until the end of the year to plough through.' Plans for the redesign were submitted to the council at the end of August. The project won outline planning approval from the then transport secretary Stephen Byers last year.
Since then engineers have been developing detailed plans, and seeking to get them approved by Hillingdon.
New plans to introduce a public transport interchange immediately outside the terminal building have resulted in the decision to reduce the amount of car parking from 8,600 spaces to 4,600. A 4,000 space car park originally joined to the terminal building has been relocated 40m away.
An approach ramp to the terminal building has also been changed. Originally it was to take vehicles to the front entrance. It has since been rerouted to feed traffic onto the top level of the car park.
Some changes have been forced on the project by a government decision to keep separate two rivers which run through the site.
In one instance three rows of office buildings have had to be scrapped.
A spokesman for Heathrow operator BAA claimed construction was still on target. He denied that any delay to the 2008 completion date was anticipated.