The First Minister has rejected Tory pleas for a fully independent education inspectorate amid claims it will take 19 years for inspectors to get round every school at the current rate.

Scottish Conservative leader Ruth Davidson said the number of school inspections has fallen from 491 in 2004/5 to just 137 last year - a drop of more than 70%.

She called for an independent inspectorate outwith the arms of the Scottish Government at First Minister's Questions.

But Nicola Sturgeon said she has already promised "a revolution in transparency for education" with its new national improvement framework, which will allow the public to see what percentage of pupils are achieving, which schools are doing well and which are not doing well.

Ms Davidson said: "Last year, fewer than 6% of Scotland's schools were inspected, meaning that under the SNP a child can go right through their school career without ever having had their school assessed.

"If that rate keeps up, it would take 19 years to get round all of Scotland's schools once."

Ms Sturgeon said: "The number of school inspections taken varies from year to year and during the period of implementation of Curriculum for Excellence (CfE) there was a deliberate, and I think very correct, decision taken to reallocate to other improvement activities, to oversee the implementation of CfE.

"So, during that period, inspectors were deployed to undertake intensive support and challenge activities of both schools and local authorities.

"It is also important to note that that work was recognised in the recent OECD report, which in relation to CfE implementation said Education Scotland has been a linchpin in providing the guidance, resources and quality assurance.

"There will be an increase in inspections in the coming years, complemented by new types of improvement activity - in particular making sure that we use the resources of the new attainment advisers that are working on the Scottish attainment challenge."

Ms Davidson said: "One former director of education said in the press this morning that inspections are now 'virtually useless' as a source of information for parents.

"So, the First Minister has urged opposition parties to offer proposals on how to improve a system in they complain about it.

"So, we say that it is time to establish an independent inspectorate, outwith the arms of the Scottish Government, so that parents know that when a school is measured that it is done entirely separately from those people who are setting the policy."

Ms Sturgeon said: "The inspectorate is independent and does demand high standards from schools.

"Local authorities also have a statutory duty to make sure that the quality of education is what we would expect."

She added: "I want to do much more than what Ruth Davidson has outlined.

"I want to give parents and the public direct information about the performance of pupils in our primary schools and lower secondary schools, because at the moment we don't really have that.

"Under the national improvement framework, once that is firmly established, we will see the percentages of pupils at every primary school across our country who are achieving the different required levels of CfE. This is a revolution in transparency for education."