The future of the practice's Stage C designs for the People's History Museum - which Heritage Lottery chiefs decided to back in January - hangs in the balance after an OJEU notice was issued by the project's client.
Current European legislation dictates that the museum must re-advertise for architects because of the monetary value of the work proposed.
As such, ASL's future on the scheme is at risk.
Culture secretary Tessa Jowell announced plans to give the project - which will amalgamate two different buildings of the museum on to one site - £7.2 million in funding earlier this year.
The museum proposes to provide increased access to collections and archives and 'increase the public awareness of a museum with a unique Greater Manchester and national significance'.
ASL partner Chris Pritchett said: 'We are delighted that the museum's HLF application has been successful.'
The architect was brimming with confidence about his potential reappointment. He added: 'This is an exciting time for the museum and we are looking forward to being appointed for the next phase of the project.'
The People's History Museum is a national centre for 'the collection, conservation, interpretation and study of material relating to the history of working people in Britain.'