John Spellar MP said the proposed tunnel under the Irish Sea between Carlisle and Belfast should be dumped "at an early stage" due to its "huge cost, geological problems and the inconvenient reality that Britain and Ireland operate on a different rail gauge".
Plans to dig the 25-mile Channel Tunnel-style rail connection have been submitted as part of a review over improving links between the UK's four nations.
The High-Speed Rail Group (HSRG) says the route, which is based on the 31.5-mile Eurostar route to mainland Europe, would also take cars and lorries.
Speaking in the Commons, former Transport Minister Mr Spellar, the Labour MP for Warley, said: "Is it not time to dump this project at an early stage, along with the garden bridge, into the bin and save a lot of money, effort and probably a few column inches in articles?"
Northern Ireland Minister Robin Walker, said: "Connectivity across the UK is vital to fuel Northern Ireland’s economic recovery and strengthen the Union.
"The Prime Minister commissioned a Union connectivity review to consider these important connections, including the feasibility of a fixed link between Northern Ireland and Great Britain."
Mr Walker also accused Mr Spellar of a "lack of ambition" over the proposals, and added: "I want to make sure that we look at all options to support connectivity to Northern Ireland, and I am grateful that we have a Prime Minister who is willing to do that."
The HSRG – which is made up of more than 20 firms involved in high speed rail in the UK and the Railway Industry Association – said the scheme would bring Belfast within four hours of London, and Dublin within six hours.
The plans would see trains bound for Belfast turn west near Carlisle, which would be used as a hub to load lorries.