Turnbull should stump up new PT funds: SA

Prime Minister Malcolm Turnbull should stump up new money for Adelaide's public transport system rather than shifting funds around, South Australia's transport minister says.

Mr Turnbull on Friday announced $43 million for a train line extension to the Flinders University's Tonsley campus.

But both the federal opposition and the SA Labor government say the money was already available.

"We would have been far more pleased if this was extra money coming into South Australia. This is redirecting money already available towards this particular extension," Transport Minister Stephen Mullighan told reporters.