Around a quarter of Westcountry pupils are failing to meet new educational standards in reading, writing and arithmetic, official figures show.
Almost 4,000 primary school pupils in Devon and Cornwall have fallen below the Government's new standards, according to national curriculum tests – known as Sats – which are taken by 11-year-olds.
Schools that fail to meet the target are considered under-performing and face being taken over and turned into academies.
Under new Department for Education rules, for the first time schools are judged on the number of children achieving at least a Level 4 – the standard expected of the age group – in reading and writing as separate subjects, as well as maths. They must ensure that at least 60% of pupils reach this level in all three subjects and meet national averages in pupil progress to be considered above the floor.
Rankings by local authority area put Devon schools top in the region, with 77% of the 6,862 pupils judged as meeting the target. This was a drop from 78% in 2012. The county was rated 57th out of 152 local authorities.
Devon County Council, which was rated above its neighbouring unitary councils as well as Cornwall, Somerset and Dorset, said the results must be seen in the context of comparatively low state funding.
Cabinet member for education Will Mumford said he was "delighted" that the county primaries were in the top half of the national achievement table and "ahead of our geographical neighbours".
"We are determined to help our schools close the gap between those who are performing well and those who are achieving high standards," he said.
"The results are a measure of the success of teachers and staff, particularly when you consider they are the sixth worst funded schools in the country. If they were funded at the national average they would have much greater financial flexibility, not only to sustain their position but to ensure our children can succeed and compete on a global basis."
The regional results chimed with national performance which saw 129,000 leaving primary school in July without hitting the expecting standard for their age in the three core subjects.
In Torbay, 77% of the 1,222 pupils made the grade, up from 72% last year – 75th position nationally – while Plymouth's 2,485 pupils also saw a rise from 72% to 77%, making it the 113th best in England. Cornwall, where there are 265 primary schools teaching 5,165 pupils, saw an increase from 73% to 75% making the grade, leaving it in 96th position.
The Department for Education said the data suggested schools are improving and had responded to the challenge of tough targets.
A spokesman said: "Schools with a long history of under-performance, and who are not stepping up to the mark, will be taken over by an academy sponsor.
"The expertise and strong leadership provided by sponsors is the best way to turn around weak schools and give pupils there the best chance of a first-class education."