Peter Hain resigned from the cabinet in January
The former Welsh Secretary has warned Wales risks "limping along" and losing out to China and India unless Welsh Assembly Government priorities change.
Peter Hain told BBC Wales he is concerned Welsh ministers are failing to plough enough investment into boosting private companies.
The assembly government had given too much priority to spending money on public services, said Mr Hain.
He said Wales needed the "best skills" to compete with other countries.
The Neath MP has maintained a low profile since he resigned from the cabinet earlier this year following the launch of a police investigation into the registering of donations to his campaign for Labour's deputy leadership.
The former work and pensions secretary has since written a pamphlet for the Labour ideas group, Wales Twenty Twenty, which was published on Thursday on the group's website.
It sets out his argument that Wales needs a bigger, more vibrant private sector and more efficient public services.
In an interview for BBC Wales' Dragon's Eye, he goes further in questioning the assembly government's spending priorities.
Mr Hain said ministers have tended in the past to focus most of their effort and investment on the public services and schemes like free prescriptions and breakfasts.
He said: "I was happy about free prescriptions and the latest decision about free hospital parking. Everybody likes that. None of us likes paying these charges.
"But is this the priority for the future is the question that I'm putting.
"We've got to make a really hard choice, focussing our spending on skills, on infrastructure, on technology, on research and development."
He added that he was worried for the future if his warning were not heeded.
He said: "I do not think Wales can compete with China and India in the future, let alone with Eastern Europe today unless we have the best skills, unless we have a growing private sector which is able to compete on the world stage.
"If we don't get that, then Wales will limp along and we won't build on the success we've had in the last 11 years.
"We'll limp along and eventually lose out so it's as big an issue as that for me."
Dragon's Eye is on BBC One Wales at 2240 GMT and BBC 2W at 2100 GMT on Thursday.