Matthew Coffey, Ofsted's director for learning and skills, has voiced concerns over falling standards at colleges across the UK, people seeking teaching jobs may wish to know.

Despite this, Mr Coffey explained that the inspectorate observed outstanding teaching and learning sessions in "most, if not all, of the institutions".

What is lacking, the Ofsted chief said, is consistency across colleges.

Explaining this trend, he pointed the blame at "over-generous" lesson observations, arguing that they should instead be "critical, constructive and accurate".

"We know it can be done," he told the Times Educational Supplement. "We know what outstanding teaching looks like and we know colleges know what outstanding teaching looks like."

Meanwhile, Joy Mercer, the Association of Colleges' director of education policy, acknowledged that Ofsted's findings are disappointing.

However, she disagreed with Mr Coffey's assertion that colleges and teachers know what is expected of them, which she claimed is one of the reasons for the falling grades.