The Conservative MP for Clacton, Giles Watling, says he'll be lobbying Transport Secretary Chris Grayling to make sure there's a better rail service if fares are being increased.
Millions of people will see costs go up by 3.6% from January, with passenger groups saying commuters will be worst hit by the rise.
Mr Watling told BBC Essex ministers must get the rail operators to provide a quality service.
"The railways are privately run, but it is the government's job to oversee the railways. We must hold them to account in a far firmer way," he said.
"If they are going to be asking for these increases, there must be serious penalties if they do not supply us with a proper service that commuters deserve."