Sefton Central Labour MP Bill Esterson said many people in Maghull are getting a second class Post Office service because the Lib Dems in Government are intent on running down the service.
Bill slammed the Tory-Lib Dem Government for failing to understand the true impact of their Post Office closure programme on communities.
Despite the imminent closure of Deyes Lane Post Office, Lib Dem minister Jo Swinson denied that there was any closure programme after being quizzed by Bill in Parliament.
Bill said he has been inundated by emails, letters and phone calls since Post Office Ltd announced the closure. Hundreds have even signed the MP's petition opposing the closure.
Bill said: "People here are rightly concerned about the closure of Deyes Lane Post Office. There are lots of older people who use that post office and who will struggle to make the trip to the next nearest post office which will either be on Moss Lane or at the existing post office in Central Square, which is already very busy.
"I also have very real concerns for the other businesses on Deyes Lane. I recently met with the Association of Convenience Stores who told me that post offices can make or break a shopping parade.
"Post offices bring people into a shopping area. If a post office closes, surrounding businesses usually experience a dramatic drop in footfall.
"That is my fear for Deyes Lane."
Bill said he has also been contacted by people concerned about the impact of an increase in traffic on Moss Lane where there are plans to introduce some post office services at the newsagents.
Bill said: "A number of Moss Lane and Dodds Lane residents, together with parents of pupils at Northway Primary, have expressed concerns about the increase in traffic at at the junction around the school should some post office services be moved to the shop there.
"They tell me the road can get heavily congested as it is, and they fear there could be traffic mayhem if the newsagent takes on some post office services.
"Post Office Ltd are justifying the closure of Deyes Lane Post Office by saying the introduction of post office services at Moss Lane will counter the negative affects of the closure. But many nearby residents and existing customers don't want the post office there because of the poor public transport links and the impact on the road.
"And Post Office Ltd's plan does nothing to counter the impact on the other Deyes Lane businesses."