The National Advisory Council for Education and Training Targets said several of the goals were within the Government's grasp. But the watchdog warned that swift action was needed to stop the British economy falling behind those of its competitors.
Worries focus on the aim to have 60 per cent of the workforce possessing the equivalent of two A-levels by 2000. At present just under 42 per cent of people have achieved the target.
NACETT's annual report, published this week, says: "Britain will now very probably need longer than four years to hit this target. We need a large and rapid increase in the number of existing members of the workforce who are qualified to level 3 (A-level).
"It will not be enough merely for more new entrants to the workforce to be qualified to that level."
There are also concerns about young people's key skills in areas such as communications, information technology and numeracy.
At present only one in ten 19-year-olds gains GCSE-level qualifications in key skills.
But NACETT researchers predict that developments like the expansion of general national vocational qualifications and the launch of secondary-level part one GNVQs will help Britain to hit the target of having 75 per cent of young people gain key skills soon after 2000.
By contrast targets for 85 per cent of young people to gain five good GCSEs or their equivalent and for 60 per cent of young people to gain two A-levels or their equivalent by the time they are 21 are thought to be achievable by 2000.
Education and employment minister Baroness Blackstone immediately announced that ministers would consult on possible changes to the targets. She said it "will provide a valuable opportunity to reflect on the lessons learned over the past six years and to look afresh at what national targets can and cannot be expected to achieve".
NACETT director, Philip Chorley, said: "We are very pleased the Government has decided to start consultation. The review of the targets needs to be open and objective. We will obviously want to listen very carefully to the views of consultees, and it would be right to wait before expressing a view about what the targets should be."
And NACETT chairman, Derek Wanless, commented: "NACETT judges that Britain can still reach the majority of the targets by the deadline of December 2000 if there is urgent action to raise attainment levels."