MPs Robert Chisholm, Megan Leslie, Peter Stoffer and Philip Toone will start their 1,500 kilometre journey at the Via Rail station in Halifax on Sunday morning, with stops in New Brunswick and Quebec.
They're making the trip after CN Rail announced it plans to abandon a 70-kilometre stretch of track between Miramichi and Bathurst in New Brunswick because it no longer carries freight on the line. Via Rail has said it can't afford to buy or maintain the line.
Chisholm said without federal help, he's worried communities east of Quebec will lose the already reduced service Via Rail provides in the region.
"It's going to have a detrimental impact on the ability of people in northeastern New Brunswick to use that line," said Chisholm in an interview on Saturday. "But we're increasingly concerned that it's going to further result in a deterioration of service."
Chisholm said $10 million is needed to maintain the New Brunswick rail line, and Ottawa should provide the funding.
"We're pressuring the federal government to step in and make sure that this line isn't abandoned and... that the upgrades are done and it is maintained and stays as part of the line," he said.
"We need to highlight the fact that this is a service that unites this country and Atlantic Canadians deserve to have a dependable efficient rail service just like the rest of the country."
Chisholm said many people in region rely on the service and while other countries are improving their rails services, Ottawa is turning its back on passengers trains in the Atlantic region.
Transport Canada said it does not intend to purchase the New Brunswick rail line.
"There is no federal legislation in place to require the federal government to purchase the railway line if CN discontinues its operation," spokeswoman Marie-Eve St-Hilaire said in an email statement Saturday.
"As previously indicated, the federal government has no interest in acquiring this rail line."