Its finding is underlined by the publication on Tuesday of an HMIE report which marks St Andrew's Secondary as an outstanding school, despite serving some of the most deprived communities in the city's east end, including Carntyne, Ruchazie and Shettleston.
The school is judged excellent in five categories, including personal and social development, expectations and promoting achievement, and partnership with the school community. Its exam results are consistently higher than those of comparator schools.
In its report to the council's education services committee, the working group reports improvement at 5-14 levels in reading, writing and mathematics, although attainment in certificate examinations has slightly fallen in line with national trends.
It adds: "Attainment remains inconsistent both across subject areas and across schools, and attainment levels of boys continue to be generally lower than girls."
The report states: "The status quo is therefore not an option. Despite the massive injection of resources by the council and positive innovations in the education service and in schools, there is still not enough support to young people in overcoming disadvantage and closing the opportunity gap."
One area of optimism is the substantial improvement this year in leaver destinations, with a gradual but sustained increase in numbers entering higher education, positive further education, employment and training figures, and a marked reduction in the number of leavers going straight into unemployment.
Such is the level of deprivation in Glasgow that it could find no other comparator authorities in Scotland. The working group therefore looked at measures taken in the London borough of Newham where there is a comparable scale of deprivation and a recent strong track record of improvement.
Angela Drizi, Newham's head of service, learning and schools, told the group that the borough had focused on the the need for language development at an early stage, boys' achievement, the need for effective training for all staff and "robust self-evaluation" by schools backed with effective validation from the authority.
The need to recognise standards should be an issue for everyone, Mrs Drizi said.
The role of ongoing formative assessment in improving attainment was backed by the working group. But the place of snapshot-style summative assessment caused a split, with union members insisting that continuing dependence on 5-14 national assessment was inappropriate.
The group's findings will be considered by Glasgow's education commission, chaired by Ronnie O'Connor, executive director of education. Membership is drawn from academic, business, health and community backgrounds.
Mr O'Connor told the education committee: "There will be a need to review existing education provision in the city and explore possible focused action required to raise the attainment and achievement levels of all pupils."
He added that the commission's remit would include areas such as leadership of headteachers and senior staff, staff competencies and the acquisition of core skills in literacy, numeracy and ICT.
The impact of nurture classes, new learning communities and formative assessment techniques would be examined, Mr O'Connor said, and he also promised a critical evaluation of existing policies on class sizes.
Proposals from the city's attainment group include:
* Flexible use of staff from P6 to S2.
* Early access to Standard grade and other SQA programmes for targeted groups of pupils.
* Masterclasses for teachers delivered by outstanding practitioners.
* Development of the coaching in context model of continuing professional development.
* Continued use of 5-14 national assessment materials by all primary and secondary schools to enable robust monitoring of progress.
* Formative assessment to be established as a key method for the improvement of teaching, learning and attainment.
* More focused intervention in the school day for pupils struggling with the conventional curriculum.
* Specialised programmes for high-achieving pupils.