A review into Scotland's secondary education system has been delayed due to the coronavirus pandemic, the Scottish government has said.
Education Secretary John Swinney said the final report from the review would now not be published until June 2021.
It had originally been expected to be released in February of next year - ahead of the Holyrood election in May.
The Scottish Conservatives claimed the delay was about "political expediency" rather than the virus.
The independent review is being led by the Organisation for Economic Cooperation and Development (OECD).
It was initially intended to examine the senior phase of Scottish education (S4-S6) following a critical report from a Scottish Parliament committee, which said there had been a "lack of clear leadership" from officials and "some narrowing of subject choice".
Mr Swinney was later forced by opposition parties to widen the review to include the whole of the Curriculum for Excellence - effectively the entire school system.
Opposition MSPs said at the time that there were "key weaknesses in some key aspects" of Scotland's schools which needed to be examined and addressed.
Documents released by the government showed a decline in the exam performance of pupils in core Higher subjects in 2019, in some cases by as much as 10%.
The delay to the review was announced by Mr Swinney in a written answer to fellow SNP MSP Gordon MacDonald, rather than in a statement to the Scottish Parliament.
The education secretary said: "We remain committed to the review of Curriculum for Excellence and are progressing this by providing the OECD with a comprehensive written evidence pack which we are co-developing with partners.
"However, it is critical that we do not make any additional demands on the system at this time.
"Therefore, following discussions with national partners and the OECD, we have agreed to postpone engagement with policy stakeholders until September and engagement with practitioners and learners until October 2020.
"This approach would see publication of the final report in June 2021."
Mr Swinney has previously said he "firmly believes" that the current system is "the right approach".
Scottish Conservative education spokesman Jamie Greene said: "Scottish education used to be the envy of the world but under the SNP we have been slipping down the league tables - the SNP government should be pulling out all the stops to find out why.
"Delaying this report until days after next year's Holyrood election seems far more to do with political expediency than Covid-19."
Labour education spokesman Iain Gray described the move as "inevitable but disappointing".
He added: "Our schools went into the current crisis facing some significant problems such as the narrowing curriculum, falling pass rates and the systematic use of multi-level teaching.
"Reopening schools is going to be challenging but this review is looking at problems of structure and resource that will still need to be addressed in the longer term."
The Scottish Liberal Democrats called for the interim findings of the review to be published ahead of the election.