Gordon Brown has refused to confirm A-levels will still be offered to young people after 2012.

The prime minister said A-levels would be offered alongside the government’s new diplomas for the next four years but was unable to confirm the so-called “gold standard” qualification would be protected thereafter.

Instead Mr Brown said ministers would make a decision in 2012 based on the initial success of diplomas.

Schools secretary Ed Balls have said diplomas could replace A-levels as the “qualification of choice” in England, with the government planning academic as well as vocational schemes.

Diplomas have received a lukewarm reception from educational professionals to date, with admissions tutors at the country’s top universities doubting whether they would prepare pupils for the most academic degree courses.

Mr Brown was responding to questions from Conservative leader David Cameron, asking the prime minister to confirm whether A-levels would be protected in the long-term.

After delaying a decision until 2012, Mr Cameron once again accused the prime minister of “dithering”.

“Anyone listening to this will recognise this prime minister cannot answer a question and cannot make a decision,” Mr Cameron claimed.

Mr Brown retorted that the Tory leader is unable to say whether he supports the government’s plan to raise the school leaving age to 18, accusing him of trying to “look both ways” on policy.

Quoting former Tory chancellor Ken Clarke, he said Mr Cameron showed “too many soundbites, not enough substance”.

Outlining the government’s plans to increase vocational education, Mr Brown said: “We are the party investing in the future, we are the party for the long-term, he is the party for the short term.”

Mr Cameron retorted the prime minister had been practicing this soundbite all weak, “and it is still rubbish”.

During their weekly commons clash, Mr Cameron also highlighted the number of government reviews launched by Mr Brown. Now totalling 52, the Tory leader said many had covered trivial subjects such as sun beds.

Mr Brown said the government was meeting public demand in re-examining super-casinos, cannabis and affordable housing.

“The opposition do not understand that the world is changing and we need to review the right thing to do,” he said.