Cathy Jamieson said a review is under way

The qualifications will be replaced with intermediate 1 and intermediate 2 level Higher Still exams, which are already in use throughout Scotland.

Another six secondaries in East Renfrewshire are believed to be ready to follow the example of St Ninian's, in Giffnock, near Glasgow, over the next few years.

Schools in the independent sector, including Aloysius College in Glasgow and Stewart's Melville College and the Mary Erskine School in Edinburgh, have already dropped Standard Grade exams, normally taken by third and fourth year pupils.

The minister said: "It's not the case that we have a situation where the Standard Grades are being completely dispensed with.

"What we have seen this week is one local authority which has decided in one of those schools to opt for using the new qualifications.

"That does not in any way devalue the existing work that is going on and the work that young people are involved in."

'Some confusion'

The minister said schools have "an amount of discretion" in choosing the best options for pupils.

"I would not expect any local authority to take a decision to dispense with Standard Grades either at subject level or across the school without having discussed that with young people, with the parents and indeed the staff," she said.

Ms Jamieson said the system needed to be "streamlined" and the Scottish Executive was conducting a review which would be followed by an announcement in Parliament "in due course".

She said: "I would recognise that there has been some confusion over the introduction of the new qualifications and what we want to see is an opportunity to clarify some of that, streamline the process but at the same time ensure that we have rigorous standards maintained."