It follows a speech in Parliament by Manchester MP Graham Stringer praising the college for boosting its numbers of post-16 learners. "Mancat has done it by paying people less - employing youth workers and other non-lecturers, who get young people into the classroom and get them qualifications," he said.
Asked if he were condoning the use of cheap labour, he said: "My boss, the Prime Minister, says we do what works. This is working."
Mr Stringer's views have angered Natfhe, the lecturers' union. Colin Gledhill, its north-west regional organiser, said: "Our members will be outraged to read of a Labour MP putting the case for FE on the cheap. To imply they haven't the capacity to adapt to the needs of Manchester's 'lost' learners is ludicrous."
Mr Stringer also attacked Manchester Learning and Skills Council executive director Liz Davis. She had written to him saying that Mancat's innovative approach to widening participation caused difficulties for funding and audits.
Mr Stringer said: "She says that it is more important to conform to LSC targets, priorities and policies than to provide money for a more successful system."
A long-running dispute over money claimed by the college for additional learning support (ALS) has resulted in the LSC demanding back pound;300,000.
Mancat principal Peter Tavernor claims goal-posts were moved by the LSC in re-defining what qualifies for ALS. He also says that staff were "continually messed about" by auditors.
The dispute triggered a one-off inspection of Mancat's ALS provision by Dr Terry Melia, former chairman of the Learning and Skills Development Agency.
However, his report says that all the ALS provision he observed could be "legitimately classed as such under LSC guidelines".