An Bord Pleanála has said it will not begin hearing an appeal into the planning granted for Terminal Two at Dublin airport until April 16th, calling into question the Dublin Airport Authority's (DAA) ability to meet its September 2009 deadline for opening the €610 million facility.

In a note on its website Bord Pleanála said the oral hearing would conclude on April 27th.

A decision would then be expected from the board by mid-June.

A decision was originally pencilled in for April 4th, according to the website.

The DAA was granted planning permission for the 75,000 sq ft terminal, which will increase Dublin airport's capacity to 35 million passengers a year, last October. This was appealed in November by Ryanair, local residents and An Taisce.

The two-month delay could have serious implications for the airport authority, which was already working to a tight deadline to make the September 2009 opening date.

The DAA will hope that the building of the terminal does not get dragged into the general election campaign.

The delay could also have significant cost implications for the project if any delays are experienced in the building .

The cost of the project has already been questioned by aviation regulator Cathal Guoimard, who is carrying out a consultation on how the terminal investment should be funded by airport charges. The airport authority said it welcomed the fact that a date for a hearing had been set.

"Dublin Airport Authority had expected a more timely completion of the planning appeals process following the planning permission granted by Fingal County Council in October, but acknowledges the heavy workload with which An Bord Pleanála has had to contend," a statement from the authority said.

"The DAA plans to have Terminal Two operational before the end of 2009, but this depends on a swift and positive outcome to the appeals process."

Even if Bord Pleanála gives the green light to the terminal, Ryanair could challenge the decision in the courts, delaying the project further.