Israel public television said on Monday details of the plan were revealed after a secret meeting between Ariel Sharon and opposition leader Shimon Peres last week.
The television report gave no further details or named the settlements in question.
Peres is said to have urged Sharon to go public with his proposal, but the premier refused, saying he needed first to gain US approval.
Another reason for postponing an announcement was a planned referendum over an Israeli withdrawal from the Gaza Strip.
But Palestinian negotiations minister Saib Uraiqat pounced on Sharon's reported proposal, saying Israel should remove all Jewish settlements from Palestinian land, not just a handful of them.
"The Israeli government should chose between settlement activity and peace. Both of these tracks cannot coexist," Uraiqat said. "They should choose peace over settlements."
"The Israeli government should chose between settlement activity and peace. Both of these tracks cannot coexist... They should chose peace over settlements"
Palestinian National Authority
The evacuation of the Gaza settlements forms part of a larger "disengagement plan" which Israel has said it will start implementing in the summer if no progress is made in the peace process with the Palestinians.
Media reports said Sharon met Peres on 19 February when the hawkish premier shared details of his unilateral disengagement plan and the estimated timetable for its implementation.
There are currently almost half a million Jewish settlers living on occupied Palestinian land in Jerusalem, the West Bank and Gaza.
All the settlements are illegal under international law.