This week's transport committee will be asked to endorse the zone, which will ban those vehicles failing to meet strict emission standards from a 1.2 square mile area of the city centre.
And the council still hopes to bring in the ban in May this year, though a two-year grace period would mean it is not enforced until June 2024.
In October, Tory and Lib Dem members of the committee backed a Green amendment calling for changes to the boundary and the grace period, and asking for evidence on how the scheme reduced greenhouse gas emissions. It resulted in the SNP-Labour administration being defeated.
But the report for this week’s meeting says officials have looked at possible boundary adjustments and a shortening of the grace period, but concluded they could not be justified.
And it warns significant changes could not be made without having to launch a fresh consultation on the scheme, meaning a delay in its introduction.
The Greens said they were disappointed, but are now expected to support the plan. They indicated they were keen to get an LEZ in place and would hope to adjust the scheme in future.
The LEZ will apply all day, seven days a week, to all motorised vehicles apart from motorcycles and mopeds and a limited list of exemptions.
The ban will affect an estimated 20,000 vehicles in and around the Capital – diesel cars registered before September 2015 and petrol cars registered before January 2006 – as well as HGVs and buses that do not meet the Euro VI emission requirements.
Tory transport spokesman Graham Hutchison said he was not surprised there had been no changes to the plans.
"The expectation was always they would come back and try to push through the same thing. There were a whole lot of things that needed looked at and revised and this is just another example of an administration which doesn't listen or take on board different views."
And Lib Dem transport spokesman Kevin Lang accused the SNP and Labour of missing an opportunity to go for a more ambitious scheme.
He had argued for the reinstatement of an earlier proposal that included, alongside the city-centre zone, a second city-wide zone banning the worst-polluting buses and lorries. Without this, it means some of the streets with the worst air quality in Scotland, such as Queensferry Road and St John's Road, Corstorphine, will be left out of the LEZ.
Councillor Lang said: “The decision of the transport committee to reject the administration's LEZ plan offered a chance to develop a better scheme and one that really tackles air pollution right across the city.
“Instead, the administration is recycling its same old scheme, a plan which is too timid in its ambition and too slow in its implementation. It will leave too many communities with unacceptably low levels of air quality and could even make the situation worse in areas around the planned city centre zone.
"This is a wasted opportunity to think again and do better, something the Council will look back on and regret in the years to come.”
Green transport spokesperson Claire Miller said: “Clearly I’m disappointed to hear that the impact of the proposed LEZ is so negligible in terms of greenhouse gas emission reduction, especially as climate is one of the key objectives in the legislation, although I very much welcome the improvements to air quality that it will deliver.
"I’ll be pushing for more action on CO2 emissions using all the options available to us, as time is ticking for Edinburgh to reach its zero carbon target.”
Transport convener Lesley Macinnes said: “The LEZ put forward for approval in October followed several years of planning, modelling and analysis, in line with national frameworks, as well as consideration of feedback received through a major public consultation.
“Additional work carried out since then to assess the scheme’s impact on carbon emissions, as well as the proposed boundaries and grace period, demonstrates that these proposals are appropriate for the city.
“The LEZ, alongside a range of ambitious projects to improve air quality, will encourage cleaner transport and support active travel, and is key to achieving cleaner air for everyone.”
Once the LEZ plan is approved by the council there is a 28-day period for formal objections, which could lead to some kind of inquiry, which may or may not involve public hearings, and then it has to be approved by the Scottish Government.