Can I still apply to MPNP if I have been refused under an immigration program of another province?

Yes you can still apply. However, you will be required to advise the MPNP if an application has been made previously to another Provincial or Federal immigration program. You are required to advise the MPNP of the results of that application including copies of any correspondence such as a letter of refusal. The application should contain sufficient information to allow the MPNP to evaluate why the factors for refusal in the other Provincial or Federal programs do not apply to the application to Manitoba.