Developer Dandara, which has turned to local firm Hodder Associates to take the huge skyscraper development forward, said the decision to change design teams was based on Sheppard Robson's lack of a 'strong core team' and 'resources' in the city.
However, Sheppard Robson has disputed the allegations, stating that, contrary to Dandara's claims, the practice actually walked away from the job because of 'issues' about the potential quality of the enormous 41-storey scheme next to the Lowry Hotel on the River Irwell (pictured).
A spokeswoman for the firm said: 'The split was amicable - but did not relate to our resourcing of the project or the strength of our team in Manchester - we've just moved to bigger offices.'
She added: 'There were other issues that influenced our decision to leave the project.
'We felt we couldn't achieve the quality of building appropriate to the site with the funding made available by Dandara.'
Despite winning planning permission last year, the scheme has not been well received by CABE, which has now examined the designs on three separate occasions.
The last time the scheme was reviewed, back in March 2006, the design watchdog said it still had fundamental concerns with the project despite revisions to the original proposals.
The report reads: 'We repeat that we think that the basic problem is one of overdevelopment; we have yet to see any evidence to suggest that the combination of this quantum of development, with the types of building forms chosen [tower and podium slab block], in this arrangement, can produce an acceptable solution.'
It goes on: 'We do not wish to comment on what we see as minor amendments to the scheme, as, as we have said previously, our concerns cannot be resolved by tinkering with the design; a fundamental rethink is required.'