Formby MP Bill Esterson said the Tory-Lib Dem government's imposed rules for boundary changes means it is impossible to stop the town being split in two.
Since the Boundary Commission announced its recommendation for the make up of new constituencies two weeks ago, which sees Harington Ward going into Southport and Ravenmeols in the new Maghull constituency, Bill Esterson has been working to try to save the town from being split.
But the MP said the rules imposed by the Conservatives and Liberal Democrats in government mean that there is no way of stopping the town being torn in two.
Bill said: "The Labour Party has been fighting this from the point that the Tories and Lib Dems announced it because we could see exactly what the consequences would be. Historic communities torn in two. And that is exactly what is happening to Formby.
"One of the criteria for the creation of the new boundaries is that constituencies must have around 76,500 voters. So it all simply becomes a numbers game for David Cameron and Nick Clegg down in Westminster.
"The result of this is that the boundary commission must disregard the impact on communities. Therefore towns are being split across the country.
"Sticking to the government's own rules, there is no way of saving Formby. The Boundary Commission will not cross county boundaries so plans which I have heard Southport Liberal Democrats suggest for a Formby and Ormskirk constituency are dead in the water.
"As a result of the government's rules, the only outcome sees Harington go into the constituency to the north and Ravenmeols go into the constituency in the south."
Bill said the Tories and Liberal Democrats are directly responsible for the splitting of the town.
Bill said: "As I have said time and time again, be that in Westminster or up here in Sefton, the government's rush to gerrymander the boundaries for their own ends under the guise of reducing the number of MPs is a betrayal of the people of communities like Formby.
"Formby will not be best served by being split up.
"It is an outrageous situation which I will continue to campaign to stop. But my fear is that the Tories and Lib Dems in government will get their own way on this.
"It is therefore galling to see the Lib Dem MP for Southport campaigning to try to save his own majority in Southport and the Conservatives here in Formby voicing their horror at the consequences of the actions of their own party.
"The time scales of the Boundary Commission's public consultations are intentionally very tight to restrict communities' and the Labour Party's ability to appeal. But I will continue to work to make the government see the long-term and devastating impact of its boundary changes and will do all I can to stop Formby from being carved up."