Parents have issued a warning over school standards after the introduction of "diluted" inspections.

Visits normally last up to a week with schools assessed on four key indicators of leadership, teaching and assessment, raising attainment and the wellbeing of pupils.

However, inspection body Education Scotland has now said 130 of its 250 planned inspections for this academic year will follow a "short model" lasting just two days.

Rather than assessing schools on four indicators, officials will look only at self-evaluation and raising attainment.

The change comes at a difficult time for Education Scotland with figures published this summer showing one in five primary and secondary schools had not been inspected for a decade or more.

The body has also been under financial pressure with core budgets cut from £21.5 million in 2017/18 to £20.5m this year. Although a recruitment campaign is under way, new figures show Education Scotland has 69 inspectors compared to 80 in 2007.

Joanna Murphy, chair of the National Parent Forum of Scotland, raised concerns about the move.

She said: "Parents hear and see great things from their child’s school all the time and the inspectorate will recognise and give praise accordingly, but parents need to know there is regular monitoring and evaluation of their school and full inspections are a key part of this.

"These short model inspections, while valuable, are only a snapshot of the school and not extensive enough to give parents the full picture of how their school is performing, or to fully involve the parents in the inspection process. We hope this is not the beginning of a trend towards shorter inspections becoming the norm."

Eleanor Conor, a spokeswoman for parent body Connect, said it would be "almost impossible" to give families the sort of in-depth analysis of how their school was performing in just two days.

She added: "We understand the importance of self-evaluation and and raising attainment, but parents will want to know that teaching and learning is the very best it can be.

"We would be concerned if this sort of shortened inspection was motivated for financial reasons and certainly we would not want this model to become the way standards are monitored in future. Increase inspections by all means, but don't dilute them."

Opposition politicians also went onto the attack blaming lack of investment and the merger of the former HM Inspectorate of Schools with curriculum body Learning and Teaching Scotland to form Education Scotland.

Iain Gray, education spokesman for the Scottish Labour Party, said: "We have long argued the incorporation of the inspectorate into Education Scotland has seen inspections sidelined.

"We were told that this was a temporary measure and more schools would be inspected again, but now it turns out Education Scotland cannot deliver properly on that promise."

Liz Smith, education spokeswoman for the Scottish Conservative Party, said staffing resources had been under "very considerable pressure" with both the number of school inspections and the number of inspectors in decline.

"In some cases pupils were moving through either seven years of primary or six years of secondary without their school being inspected. That is not acceptable by anyone’s standards.

"There is undoubtedly a case for a small number of limited school inspections to take place, but parents have a right to expect that the overall policy with school inspections will be both comprehensive and rigorous."

Tavish Scott, education spokesman for the Scottish Liberal Democrats, said many parents would question the value of shorter "tick box" inspections.

Ross Greer, education spokesman for the Scottish Greens, added: "It is now past time that we had a root and branch review of what we inspect schools for and how we do it. What we have certainly isn't working."

However, a spokeswoman for Education Scotland said the shorter inspections would still deliver the correct level of challenge to schools.

She said: "The short model inspection is as robust in its scrutiny as a full inspection model. Inspectors undertaking a short model inspection make the same professional judgements and gather a wide range of evidence to allow them to do so.

"This evidence comes from quantitative data and information, the views of people involved and observing children’s and young people’s learning at first hand. In the short models of inspection, we grade a fewer number of quality indicators and have adjusted the time we spend in schools accordingly."