Mr McConnell insisted it would be “irresponsible” to completely abolish charges on the Forth while detailed plans are being drawn up for a new crossing.

The Executive has committed to build a £1 billion replacement, as the bridge could have to close to heavy lorries by 2013 because of corrosion.

He said, “That is why Labour will remove the Forth tolls for vehicles with more than one person in them. That way we provide an incentive for people to car-share, we reduce congestion, and we may help to extend the life of the current bridge.”

But he said that removing the tolls on the Tay Bridge would help cut congestion in Dundee City Centre, adding, “This is a sensible, responsible way to move forward.”

Shona Robison, who is campaigning to be returned as MSP for Dundee East, said, “Jack McConnell is panicking under pressure from the SNP and has been forced into following where the SNP has led.

“He has had five years to scrap tolls and has done nothing about this.”

Speaking at the Wellcome Trust Biocentre at Dundee University, Mr McConnell also promised to create a new Scottish Institute for Life Sciences in the city if Labour win a third term.

The First Minister said he had been convinced of the need for the centre by Professor Sir Philip Cohen. Mr McConnell said, “I think it is wrong that there are three centres for Life Sciences in the south of England, but none in Scotland.

“I believe it is important we commit to that for the next term of the Parliament and the right choice for the location is Dundee.”

Earlier, Sir Philip said, “I personally believe a Scottish Institute for Life Sciences would attract more world-class entrepreneurial scientists to Scotland and the obvious place to set up SCILS is here in Dundee.

“My vision for SCILS is that it would be set up in Dundee where it would benefit from synergy with the exceptional biomedical science environment at the University of Dundee.”

Earlier, the First Minister walked through the Overgate Centre with Labour’s two parliamentary candidates for Dundee East and West, Iain Luke and Jill Shimi.

They greeted several shoppers and, afterwards, Mr McConnell said they had been given a warm response. He said, “It was very positive. What came through was just how well known Jill Shimi is.”