TORONTO - The Toronto Port Authority wants to take another stab at building a pedestrian tunnel to the Billy Bishop Toronto City Airport -- and the travelling public will foot the bill.

This time, it is proposing a Public-Private Partnership for the project, which is estimated to cost $45 million.

As a result, the Airport Improvement Fee (AIF) would rise to $20 from $15, although the TPA noted that the equivalent fee at Pearson International Airport is $25.

"In light of the popularity of the Billy Bishop Toronto City Airport with travellers and airlines, it's the right time to move forward with the pedestrian tunnel initiative," Mark McQueen, chairman of the TPA board of directors, said Friday in a news release.

The airport is expected to handle one million passengers in 2010, compared to 25,600 in 2005. As a result, the TPA said more than one point of entry is required to the island airport.

Passengers of Porter Airlines, the main user of the airport, currently take a 90-second ferry ride to the airport.

The TPA would continue to operate the Marilyn Bell I ferry across the Western Passage to provide access to fuel and catering vehicles, construction equipment and ambulances.

"The TPA's existing ferry service does not operate between midnight and 5:30 a.m. and as such, the tunnel would provide Ornge paramedics and their patients safe, reliable, round-the-clock access to downtown Toronto hospitals," it said.

In October, the TPA said it had given up on an attempt to build a tunnel by using federal stimulus money.

At that time, it estimated the cost at $38 million. CommunityAIR, which opposes the very existence of the island airport, claimed the TPA's own consultants said it would cost at least twice that amount.

In Friday's news release, the TPA said, "The winning consortium is also expected to take on 100 per cent of the risk associated with any cost overruns during the construction phase of the tunnel project."