Almost half of primary school pupils in Medway attend schools ranked inadequate or requiring improvement, making the area the worst in the country.
Only 53% of primary pupils in the area attend good or outstanding schools, down 6% from 2012/13, according to a new Ofsted report.
The report has ranked Medway as 150th out of 150 local authorities in England for the percentage of pupils attending good or outstanding primary schools.
Kent County Council is ranked 131st with 71% of pupils at good or outstanding primary schools.
The report has led to calls for the councillor responsible for improving education, Cllr Kelly Tolhurst, to stand down.
Cllr Adam Price, Medway Labour’s education spokesman, said: “It is staggering that the portfolio holder responsible for educational improvement can claim that schools are on a ‘journey of improvement’ when the reality is we have fallen 6%.
“We have not seen the improvement our parents, teachers and children deserve, and for that reason the portfolio holder should consider her position, and stand aside for someone who is solely focused on improving education in Medway.”
Last year Medway was ranked second to worst with 59% of pupils in good schools. Wolverhampton in the West Midlands was the worst with 56%.
Cllr Kelly Tolhurst said: "In late 2012, Medway brought about a change in leadership in children’s services to drive through improvement. This was followed by a change to the portfolio holders the following year.
"Since then, we have started on a targeted approach of improvement and seriously challenged schools. In the past year provisional figures show we have seen improvement in Key Stage 2 at level four, including English and maths, with a 3% year on year rise to 75% of primary school children now achieving this.
"We appreciate many of our primary schools need to continue their journey of improvement and indeed have embarked on a series of actions in the past two years which have seen Medway Council really challenge leadership in our schools.
"This has led to significant movement of head teachers whereschools are not delivering for their children. That is not to say that all teachers that have moved from schools in the past two years have done so for this reason. We have some outstanding headteachers and teachers, but we need more.
"Bringing about such improvement is a big job that cannot be done overnight. Schools and the education community are fairly autonomous organisations and the council seeks to work with them, and provide strategic direction across the more than 100 schools in our area.
"While it does not have the powers to just direct a school to do something, our school improvement teams work very closely with schools and many – such as St Mary’s Island primary school which recently moved from special measures to a rate of good – say they could not have achieved such a great leap in their rating without our help and guidance.
"That said, we will never seek to be complacent when it comes to the education of children and continue to drive through improvement and challenge schools that we consider are not delivering.”
She added that the council has been consulting with schools and the education community to create a draft school improvement strategy. It's aims would be to ensure GCSE results stay above the national average and also to lift Key Stage 2 Results at Level four to the national average by 2016.
Tracey Crouch, MP for Chatham, said: “This comes after more thorough and rigorous inspections than in previous years, but nevertheless we are still bottom and that is disappointing. There has to be an urgent school improvement programme developed.”
She added that there is a distinct gap between primary schools and secondary schools which are “actually doing rather well”.
Medway ranks 41st out of 150 local authorities with 84% of pupils attending good or outstanding secondary schools. However, this is down from 89% the previous year when Medway secondary schools were in the top 30 in the country. Kent is 37th, with 85%.
Cllr Tolhurst said: "We welcome the news that our secondary schools are listed among the top third in the country in Ofsted’s report today with all but two of our secondary schools listed as good or outstanding and none listed as inadequate or in special measures."
Mark Reckless, MP for Rochester and Strood, said he will be contacting schools minister David Laws to arrange an urgent meeting about Medway’s primaries.
He said: "This is an appalling performance and it's time the Conservatives on Medway Council ended their complacency about this.
"There is good provision at secondary level but our problem is at primary level and I feel for far too long this nettle has not been grasped, consecutive portfolio holders have not dealt with this issue."
Peter Reed, an independent education adviser, said: "To no one’s surprise, except Medway Council’s, Medway has come well bottom of the national league table for Ofsted outcomes.
"This decline, both absolute and against the national trend, was absolutely predictable, with 11 schools declining in performance, against just four improving, and no Outstanding schools at all this year."
Early Years HMI (Her Majesty's Inspectorate) has delivered improvement seminars to all private, voluntary and independent early years settings in Medway as it has been identified as a priority because "children were poorly prepared for primary school and did not catch up".
Early Years provision in Medway is the lowest in the South East with only 67% of settings judged as good or outstanding by August 2013.
HMI have also provided additional support and challenge to the three weakest-performing local authorities in the South East, according to the report: Medway, Portsmouth and the Isle of Wight.
The report said: "These local authorities are making important improvements, although the outcomes for young people are still not strong enough.
"The rate of improvement for inspection outcomes is slower in the South East than in all other regions.
"Ofsted has taken an increasingly tough stance when inspecting those schools where disadvantaged pupils do not do as well as they should.
"It is right that inspection outcomes should reflect their weak outcomes and not allow them to be hidden among the strong outcomes of others."
The Medway Labour Group will be tabling a motion at the next full council meeting with an action plan to support improvement under a new and focused Director.
The group wants a mandate to bring Academy Schools under greater local authority oversight, a commitment to solely qualified teachers in our schools and measures to encourage governor recruitment.