Deputy Opposition Leader Tanya Plibersek has warned universities to toughen their admission standards for teaching degrees or face a mandatory cap on student numbers under a Labor government.

In a hardening of Labor's position – as fresh data again shows a decline in entry scores for teaching degrees – Ms Plibersek promised action to ensure universities are drawing student teachers from the top 30 per cent of high school graduates, amounting to an ATAR cut-off of about 80.

"Labor wants the best and brightest Australians studying teaching. If universities don’t do the right thing and fix this themselves, a Labor government will make them. We hope we don’t have to do this, but we will if we have to," she told The Sunday Age and The Sun-Herald.

Deputy Opposition Leader Tanya Plibersek, pictured with school children at Questacon in Canberra, is urging universities to toughen their admission standards for teaching degrees or face a mandatory cap on student numbers under a Labor government. Credit:Elesa Kurtz

"Labor wants our young people competing to get into teaching in the same way they compete to get into medicine. We want young Australians with a track record of achievement, motivation and capability to teach the next generation. We want a career in teaching to be a first choice, not a fallback."