JACK McConnell yesterday admitted that tolls on the Forth Road Bridge might have to be retained to help pay for a new crossing.
The First Minister said no "snap decision" on scrapping tolls could be made because building a new bridge or tunnel would cost more than £1 billion. However, the SNP accused him of "flawed logic".
Mr McConnell's comments came as ministers await a
report into the future of bridge tolls, which is expected to recommend retention on the Forth because removing them would have limited economic and social impact.
Labour is committed to "positively examine" scrapping tolls, while Sir Menzies Campbell, the Liberal Democrat leader, called at the weekend for the Forth tolls to be removed.
Mr McConnell, who was taking part in an "Ask Jack" event, organised by Radio Forth at an Edinburgh school, said: "I don't think we can [take] a snap decision to get rid of the tolls - particularly because of the fact we are going to have to pay well over £1 billion to replace it with a bridge or tunnel."
He described the situation as "difficult". He said: "The popular thing for any politician to say, even today, would be to abolish them."
However, the First Minister said the cost of a crossing would be "massive" and there were problems of traffic congestion with the existing bridge.
He said: "It is a complex issue - we need to review the toll regime properly, and we need to continually try to improve public transport. I think the bridge is already too busy, and used too much for its construction.
"If we remove the tolls, I think most people would assume the number of people who use the bridge would go up.
"And if that situation arose, the life of the bridge might become even shorter."
Mr McConnell's views echo those of Tavish Scott, the Liberal Democrat transport minister, who has said the Scottish Executive cannot remove tolls from the bridge until it has a clearer idea of how a replacement crossing will be financed.
But Fergus Ewing, the SNP's transport spokesman, said: "It's nonsense to suggest tolls might have to remain because a new crossing is required.
"The bridge is just another road, and we pay for roads through fuel tax."
