Sefton Central Labour MP Bill Esterson said one of the greatest concerns about building on much of Sefton's greenbelt is the fact it is prone to flooding.
The MP quizzed the Secretary of State for Environment, Food and Rural Affairs, Owen Paterson MP, in Parliament on Monday evening.
Referring to developers' plans to build more than 300 houses in Formby and a further 500 in Lydiate - both in areas which are prone to flooding - Bill asked the Minister: "Developers in Formby and Lydiate in my constituency want to build on farmland that often floods. Will he ensure that the Chancellor and the Secretary of State for Communities and Local Government do not prevail in their desire to force through development in areas, such as my constituency, that already have a significant problem with flooding?"
In response, Mr Paterson said: "The national planning policy framework is absolutely clear that development should be located away from flood risk wherever possible."
Bill said in light of the Minister's response, the developments in both Formby and Lydiate would be very risky.
Bill said: "The Minister made clear that any future developments 'should be located away from flood risk'.
"It is perfectly clear that land which developers have their sights on in Formby and Lydiate are prone to flooding. Great swathes of those stretches of land are regularly submerged whenever we get heavy or prolonged rain.
"In the last few days we have seen roads around this part of the world submerged as water levels rose. Just a couple of months ago we had people in Sefton Central being forced out of their homes because of floodwater. Some are still not back home as their houses are still being repaired.
"It would be wrong to let developers build on farmland which floods. Living in properties which might flood would blight the lives of those who move in and make flooding worse for the surrounding, existing, communities, where there is already a problem, as there would be less drainage than now."
Bill said developers should not be allowed to "chase a quick profit" at the expense of the rest of the community.
Bill said: "We need affordable properties for our young people. We need smaller properties so older people can downsize when they want to. But the decision about where these are built must be in the hands of the communities themselves and those communities should benefit from being allocated some of those properties.
"Developers must not be allowed to build on flood plains and areas which flood, only to move on with a hefty profit once the properties are built, leaving the new homeowners and the rest of the community to pick up the pieces.
"How would these new homeowners get home insurance? And how would the existing community get insurance if the problems of flooding become worse?
"We need suitable properties. But we need them in the right place.
"Flood land in Formby, in Lydiate, or anywhere else is not the place for new housing."