Media playback is unsupported on your device Media caption The Welsh Conservatives said pupils should be separated by ability at 14 into academic and vocational streams

"The best elements" of the old grammar school system would be revived if the Welsh Conservatives took power in Cardiff Bay, the party says.

It believes the move would raise standards although it is not calling for a return of the 11-plus exam.

The party said pupils should be separated by ability at 14 into academic and vocational streams.

The head teachers' union said the "intriguing" idea currently left questions unanswered.

There are no remaining grammar schools in Wales and only 164 in England.

Analysis The last grammar school in Wales went in the 1980s, and there are only 164 left in England. But their supporters say they helped pupils from poorer backgrounds to get on, and they pushed up standards. The counter argument is that it was very divisive to have this exam at 11 years old, separating pupils out at that age into two streams. Angela Burns isn't saying we should revive the 11-plus - but she does want to see pupils separated into two streams, one academic, one vocational. Her reasoning is that various studies have shown Wales falling behind in comparison to other countries, and it's time to take radical action. There are unanswered questions - not least whether there would be an exam at 14 to decide which stream pupils enter, or whether everyone would still take GCSEs. But the politics is interesting too; grammar schools are a touchstone issue for the Tories - they're popular with the grassroots and many MPs, but they make the leadership nervous. David Cameron isn't in favour of expanding selective education.

Writing in the Daily Telegraph, the Welsh Conservatives' shadow education minister Angela Burns said: "I think it is time that we revisited the successful elements of grammar schools and sought apply it to a modern Welsh system.

"If we did that we might again see a Wales where excellence is championed in a dual education system."

Prime Minister David Cameron is not in favour of increasing selective education in England, a policy that has caused disquiet in the Conservative party and led to the resignation of front-bencher Graham Brady in 2007.

Under devolution, the Welsh Tories are free to set their own policy independent of Mr Cameron's party in London.

A Conservative Central Office spokesman said: "We don't have an opinion on Welsh education policy because it is a devolved matter."

If they were in power, the Welsh Conservatives would not adopt the old system of academic testing at 11, which Ms Burns concedes was divisive.

But she insists the dual education system would raise standards and help brighter pupils from poorer backgrounds.

Welsh Conservative leader Andrew RT Davies said too many pupils were coming out of education with the wrong type of qualification for employers and it was about making the right choices - academic and vocational - at the age of 14.

Pupils would remain in the same schools where appropriate but some would carry on with academic subjects, while others would take vocational options.

Media playback is unsupported on your device Media caption Ex-head Mal Davies tells BBC Radio Wales there are dangers in reviving elements of the grammar school system

Mr Davies told BBC Radio Wales they wanted to "bring the best elements of the grammar school system" and that the current system was failing in Wales.

"Ultimately you are good at vocational courses that would qualify you for the workplace in a vocational manner - or academia," he said.

"What we have at the moment is a system that actually constrains academic achievement and this homogenised blob that says everyone is the same.

"That's no good for the 21st Century. We have got to be pushing academics and we have got to be pushing vocational courses and have parity between the two."

He added: "If we're going to develop an economy that's fit for the 21st Century we have to have learners coming out of education with the qualifications that are robust and appropriate."

Ms Burns cited research from London University's Institute of Education which she said shows that the abolition of grammar schools has blocked disadvantaged pupils' "escape routes" to top universities and high-paid professional careers.

'Unanswered questions'

She added: "Instead of separating academic children from their more vocational counterparts, we could see the benefit of creating two equitable streams of education, one alongside the other, a dualling that begins at 14 - giving children the chance to develop important core subject skills before embarking on their chosen path."

Welsh Education Minister Huw Lewis said he "thought someone was pulling my leg" when he was told of the Welsh Conservatives' proposal.

Mr Lewis wrote a series of messages on Twitter criticising the policy, saying the Labour-run Welsh government was "committed to excellent schools for all, not encouraging a parental scramble for advantage".

There were numerous unanswered questions about the Tory plan, he said, including whether pupils would remain in the same school after the age of 14 and whether all would take the GCSE qualification.

The head teachers' union called it an "intriguing development" for Wales, where grammar schools were a "distant memory for most."

Anna Brychan, director of NAHT Cymru said the proposals currently raised more questions than they answered.

"The grammar school system is remembered positively by those who benefited from it," she said. "That same system disenfranchised very many of our young people.

"Ultimately the test for us will be what system can give all pupils the best opportunity to learn and prosper."