The meeting took place during a visit by the minister to leading high street chemist Boots and the firm was among campaigners trying to wring out concessions from the minister, claiming Nottingham businesses were being used as guinea pigs.
Businesses fear they will be crippled by proposed charges that will start at £150 plus VAT for every parking space provided to staff and rise to £350 plus VAT in 10 years.
Business leaders presented Spellar with a detailed argument against the scheme as part of their STOP campaign to block the charging plans.
But Spellar deflected the protests, falling back on the Government's argument that it was up to local authorities to decide whether parking charges were appropriate.
Nottingham is one of the first authorities to push forward with a workplace parking charge scheme, which could bring in £10 million a year when introduced in 2004.
Companies will be charged for every parking space they provide in a bid to encourage car sharing among staff and use of alternative transport. Companies would deduct the cost from staff salaries or meet the charge themselves.
Boots has already been highlighted by the Government in several reports as leading the way in green transport initiatives, including a bus service for staff and promotions for cycling to work and car sharing.
But the firm still needs thousands of parking spaces after it merged operations at an out-of-town business park to reduce staff travel.
A spokesman for Boots said: 'By moving here, we cut back on staff travel between sites. The council claims workplace parking will reduce congestion, but we don't believe that it will. In essence, Nottingham is being treated as a transport laboratory. There is no evidence at all that the tax will reduce congestion.'