Children's Minister Roderic O'Gorman is objecting to plans for a €40m co-living project in Castleknock.
Bartra Capital wants to demolish Brady's pub on the Old Navan Road and build a five-storey co-living scheme of 210 beds.
Sinn Féin deputy Paul Donnelly and former Solidarity People Before Profit TD Ruth Coppinger have also submitted objections to the plan, as have many local people.
The opposition comes as the Government moves to halt further co-living developments.
Fianna Fail Housing Minister Darragh O'Brien confirmed guidance will be issued to councils that there should be a presumption to refuse planning permission for co-living shared accommodation developments.
Applications already made will not be affected by the effective government ban.
Richard Barrett's Bartra is planning to spend €130m building four shared co-living sites in the capital that have either
secured planning permission - in Dún Laoghaire and Rathmines - or are currently in the planning process, in Castleknock and Ballsbridge.
In a joint objection against the Castleknock plan, Greens TD Mr O'Gorman and party colleague councillor Pamela Conroy said the proposal "constitutes over-development of a suburban site in the middle of traditional residential housing estates".
They also expressed concerns over the plan in the context of Covid-19.
They said that in a Level 4 or 5 situation they "would be deeply concerned for the mental well-being of someone living in such isolating, restrictive conditions".
In a joint objection with Sinn Fein councillor Breda Hanaphy (SF), TD Paul Donnelly claimed the development would be visually obtrusive and have a significant negative impact on the character of the area.
"The development of co-living properties is a retrograde step in the development of not only Dublin 15 but for the city," they said.
Ms Coppinger lodged a joint objection with party colleague councillor John Burtchaell.
"Dublin 15 has a serious housing crisis, but this is not the type of housing that is needed," they said.
The Bartra Castleknock proposal is the second time the company has lodged the plan with An Bord Pleanála.
The appeals board gave the project the green light last year, but this was successfully challenged by a local residents' group in the High Court, which quashed the board's decision last June.
A report lodged with the new plan says the risk of transmission of Covid-19 among residents is "very low".
Bartra's planning consultants Thornton O'Connor Town Planning have told An Bord Pleanála that "the proposed scheme will provide a high-quality, contemporary designed, shared-living scheme which will be easily assimilated into its surrounding context through its high-quality design".