Sir Peter Soulsby has rejected a request to trim back the budget of a scheme to revamp an historic Leicester street.
Councillors asked the city mayor to consider cheaper options to his proposed £500,000 refurbishment of Guildhall Lane.
The road surface is to be re-laid and evened out in a bid to improve links between the city's shopping streets and its historic attractions such as the cathedral, the Guildhall and Sir Peter's proposed £4 million Jubilee Square plaza.
Last month, members of a city council scrutiny commission questioned whether it was justified to spend that amount of cash on the road at a time when the council was under extreme financial pressure.
Sir Peter agreed to reassess the scheme but has now announced he will not be making any changes to his original plan.
In a letter to councillor Mohammed Dawood, chairman of the council's overview scrutiny committee, the mayor said: "In setting the budget, officers have been understandably cautious given the context.
"Very significant repairs to the highway structure will be needed because of their age and previous utility works.
"The works carried out will be in a highly sensitive conservation area and, in particular, in close proximity to the Guildhall and the cathedral.
"It may also be necessary to alter the underground services so a sensible contingency sum is included to allow for all these factors.
"The materials used to rebuild the street will be high-quality block paving and red asphalt and appropriate for the historic context.
"They have been selected to deliver good value for money and complement the more expensive Porphyry that is being used at Jubilee Square and the Cathedral Gardens.
"The cautious budget estimate provided by officers is, I believe, appropriate at this stage of the project but I hope the actual costs will be significantly lower as the project proceeds through its building phases.
"I have, therefore, concluded that the proposal put to me is soundly based and of high priority. Because of this, I now intend to reconfirm my approval."
Labour group chairman councillor Patrick Kitterick accepted some improvements were needed but had asked the mayor to look at making savings in the scheme.
Coun Kitterick said: "In 2008, it cost £105,000 to resurface Loseby Lane to a good standard and that has stood the test of time. I think we have missed a chance to bring down the cost of this scheme but this might be something on which we have to agree to disagree."
Tory opposition member Ross Grant said improvements could be made to the street at half the stated cost.
