John McAslan attacked officials at Glasgow City Council as "not that bright" after they pulled the plug on the £15million plans, despite spending in excess of £100,000 on the initiative.
Insisting he would continue to press council leader Gordon Matheson to reinstate his design, Mr McAslan said he believed his winning blueprint had been pulled, in part, because it was not the design many in the authority had wanted.
The London-based architect said his plans could have been delivered for about £3m less than the proposed budget and without tampering with the Square's history by retaining all the statues.
Mr McAslan said: "Gordon Matheson has chosen to ignore the process, the views of the jury and his officers, for whatever political reasons and is now off to work up his own proposals.
"He has wasted time and resources. It is not the way to behave or to run a serious process.
"It seems to me he didn't like the result of the competition and terminated it.
"There is incompetent governance at the heart of the city council and Gordon Matheson has allowed this to happen. He is the chap ultimately responsible.
"We will continue to pursue this positively and while there may be legal avenues that is not a route we will be going down."
A council spokesman: "Under the procurement process for the design contest, the jury had to conclude its deliberations and choose a winner, and that part of the process was completed on Monday.
"The next stage was for the council to decide to award the contract to the winning company."
CITY SPLIT OVER DECISION – PAGE 13