Former MLC Marlene Maska and chartered surveyor Keith Dalrymple have raised significant concerns about the Area Plan for the North and West, arguing it promotes urban sprawl and undermines town regeneration.
The plan is due to be debated by Tynwald next week.
Mrs Maska stated the plan designates large tracts of greenfield land on the outskirts of settlements, which “discourages people to invest into the Brownfield sites that exist all over the island”.
Mr Dalrymple called the plan “flawed,” stating it is “predicated on a false premise” of major population growth.
He warned, “It favours not urban regeneration, but Urban sprawl, and it undermines the viability of what we’re seeking.”
Both emphasised the lack of necessary infrastructure and the economic challenge brownfield development faces against cheaper greenfield options.
Ahead of the Tynwald debate, Mrs Maska urged members to “pause and consider,” adding that if the plan is abandoned, “we’re not going to fall off the end of the world.”