When operational, the Â£10bn nuclear plant is expected to create 850 permanent jobs and should start generating power by 2025.
Reports in Japan suggest owner Hitachi will suspend the project if new investors fail to come forward.
But Horizon - a subsidiary it has charged with delivering Wylfa - said it was confident it would proceed.
A spokesman for Horizon told BBC Wales' Newyddion 9 that parent company Hitachi had made it clear from the start that new investors would be required to complete the Wylfa Newydd scheme.
"It's not Hitachi's intention - and never has been - to completely sell Horizon," he added.
"We're very confident that we will attract the investment required for this project."
A third and final consultation into the plans has been held and Horizon hopes to submit a planning application, known as a development consent order, later this year.
But campaigners against the nuclear site, Pawb, speculated there would be no new plant unless the UK and potentially Japanese governments provided guarantees to draw in investors.
"Yet again the poor old taxpayer would be asked to fork out," a statement from the group said.
The company behind Wylfa Newydd on Anglesey has denied its owner is trying to distance itself from the scheme.