People from Manchester that use its local dialect are also called Manc speakers. This accent is very different from others nothern dialects but has similarities with north-east modern english. As a consequence of the Industrial revolution Manchester fastly expanded. People mainly immigrated from Ireland but also other parts of Europe, obviously because of job opportunities and it created a local diversity.
There is this very funny article where sociolinguists from the Manchester Metropolitan University created an "accent and dialect map" dealing with Greater Manchester and illustrating inhabitants' opinions about the area's sonorities.
Here are some useful links, the first one is a local article published on "Manchester evening news" presenting local phrases and expressions, another one from the same website that is a pocket dictionary as I would say, and finally this one hour conversation with locals about the dialect.
David Threlfall :
He is an actor from the famous TV series Shameless where mancunian local accent is significantly represented. The first extract that you will find down is a recap of ten years of show. The second is a very gruesome speech which is finally very appropriate for us to illustrate this type of accent.
Lesley Nicol :
She is an actress that grew up in Manchester and her accent is very sweet. She played in Downton abbey and in that interview, she's speaking with Sophie McShera which is from Bradford (Yorkshire) which sounds really posh in this interview and in the show. Lesley Nicol also portrayed a character in Shameless and Once upon a time.