Children in the catchment area for Harris Academy and Menzieshill High School will have a place at the new Harris building, the council has guaranteed.
Dundee City Council education convener Stewart Hunter made the promise amid parent fears of over-capacity.
West End councillor Fraser Macpherson, a member of the Harris Academy Parent Council, said he is supporting parents seeking answers as the council considers redrawing the catchment areas if Menzieshill High School closes.
The proposals would see all Menzieshill pupils transferred to the new Harris Academy when building work is complete in 2016 but Mr Macpherson said: “There must be clear clarification about capacity.
“The main concern raised by my constituents is whether or not when Menzieshill catchment area is added into Harris, would there be enough capacity at the new Harris to accommodate all the pupils?
“The reassurance many people are looking for is to make sure we don’t go over capacity as we have seen in the past in Craigowl Primary.”
In his report to council, education director Michael Wood states that only 590 pupils out of the current 940 roll come from the Harris Academy catchment area and the rest are through placing requests.
There are 487 pupils on the school roll for Menzieshill High School.
The new Harris Academy will have the capacity for 1,309 pupils and Mr Hunter said that, although it would always be tight, children in the catchment area would have places.
Mr Hunter said: “I understand why parents would be concerned and, with the popularity of Harris, we do realise going ahead it is going to be tight.
“If these proposals go ahead, pupils in the catchment area for Menzieshill and Harris will go to Harris.
“We have crunched the numbers and, taking current housing projects into consideration, we will be pretty much at the 1,309 capacity.
“There will be less people going through placing requests but we built the schools for the catchment areas.”
He also guaranteed no currently placed pupils will be taken out of schools but there will be less room for placements in future.
He said: “At the moment we have less placement requests because people don’t want to go to the Rockwell site but in the new site we expect numbers to go up to their previous level.
“We can guarantee no children with placements will be taken out of school.”
The proposals will be debated by councillors on the education committee on Monday and, if it goes ahead, a consultation process will begin in the new year.
Mr Hunter urged anyone with concerns to make their voices heard through the consultation.