Wales should be "sceptical" about nuclear power, a Welsh Labour leadership candidate has said.
Mark Drakeford's comments have been attacked by his election rivals - Vaughan Gething and Eluned Morgan.
Both suggested his views could hit the prospects for the planned Wylfa Newydd nuclear power station on Anglesey.
Mr Drakeford said its local impact should be borne by the developers, but that did not mean that the plant cannot be built.
The winner of the Welsh Labour contest would take the helm of the Welsh Government as first minister - he or she would not have powers over large power stations or Wylfa.
That lies with the UK Government in London, which opened talks with the Japanese firm behind the plant in the summer.
However, Mr Drakeford's comments appear to strike a more cautious tone to the project than the existing First Minister Carwyn Jones, who said it has the potential "to transform the Welsh economy".
In a Twitter video Mr Drakeford said Wales' attitude to nuclear power should be "sceptical".
The finance secretary said the "bar" should be set high over "developments that would have a direct impact on the Welsh population".
Mr Drakeford, the finance secretary, said he understood the Wylfa Newydd project was "potentially a very big investment in that local economy".
But he said "the long-term interests" of people who live on Anglesey should be protected.
He also vowed to establish an independent expert committee to provide "the best possible advice on the impact" Hinkley Point C in Somerset could have on people in Wales.
Mr Gething, the health secretary, called Mr Drakeford's comments "troubling".
"I'm concerned about the potential impact upon the economy for Anglesey and about the broader consequences for North Wales," the Cardiff South and Penarth AM said.
Eluned Morgan said she was a "recent convert to nuclear power and the reason for that is climate change".
"What makes Mark's comments even more worrying is that the development at Wylfa in particular is at an extremely sensitive time," the Welsh language minister said.
"Any indication that the Welsh Government isn't supportive now could damage the project in the long term."
Speaking to BBC Wales, Mr Drakeford said he recognised "that a new leader does not change party policy, which is that nuclear power is part of the mix for future energy."
He accepted that "powerful voices on Anglesey" say that Wylfa is important, but Mr Drakeford said the "legacy of the development should not be detrimental to local people".
He said it should "not disadvantage local housing or suck up workers from other areas of work such as social care on the island. It shouldn't impact on the welsh language nor leave a damaging legacy for tourism."
"That doesn't mean we cannot go ahead, just that if it does we need to deal with those issues and make sure the costs fall on the developer," Mr Drakeford added.