"It defeats the whole purpose of bus lanes - it's a really dumb idea," Mr Lee said yesterday. "It is taking away the one advantage public transport has, of speed.
"Once you open the door for taxis, you open the door for everyone."
Mr Lee, who is a council appointee on Auckland Transport's board, said he believed the organisation had overcommitted itself without proper consultation with the council or bus users.
But Auckland Tramways Union president Gary Froggatt said he would support a trial to see whether taxis would pose difficulties for bus drivers trying to meet timetables.
"I don't really think the odd taxi in a bus lane is going to cause problems.
"Cyclists and motorbikes cause more problems than I think taxis will."
Auckland Transport operations chief Greg Edmonds has written to the Taxi Federation saying the council body is preparing a trial application to the Transport Agency.
That would be "a reasonably complex matter" for which new signs and markings would be needed to create a new form of special vehicle lane.
It is understood taxis would be allowed in such a lane, whether carrying passengers or not.
Mr Edmonds said a likely aim would be to see if that would encourage a switch to a combination of public transport and taxi use by private motorists.
It would also assess whether cyclists would be put at any extra risk.
He warned a trial would be terminated early if there was any indication of significant impact on public transport use, which Auckland Mayor Len Brown wants to double in 10 years.
Although the federation also nominated Great South Rd and Grafton Bridge, Mr Edmonds indicated they probably carried too many buses for Auckland Transport to be "comfortable" including them in an initial round of trials.
Taxi trial
Candidate routes for trial of taxis in bus lanes:
Mt Eden Rd
Sandringham Rd
Ruled out for now (but may be considered for future trials):
Gt South Rd
Grafton Bridge
Now allowed in bus lanes:
Buses with seats for nine or more passengers
Bicycles
Motorbikes
Emergency vehicles
Cars intending to turn off the road in the next 50 metres.