TAG Oil has started drilling an exploratory well near Dannevirke, with opponents accusing the Canadian company of not consulting widely enough.
The Ngapaeruru-1 well began commenced at 4.30am on Monday, targeting petroleum-rich rock formations at about 1800m.
TAG hopes to emulate its continuing success in Taranaki and says the East Coast Basin has a multi-billion barrel oil and gas potential.
Chief operating officer Drew Cadenhead said the drilling was the culmination of six years work on the East Coast.
"We're excited to finally be here," he said.
"While we know drilling conditions can be tricky in this over-pressured basin, our drilling department is well prepared to complete these operations safely and with minimal impact to the environment."
TAG CEO Garth Johnson said it was an exciting time both for TAG and New Zealand.
"It is a significant step towards understanding the true potential for oil and gas in the East Coast Basin."
There had been substantial engagement and consultation with stakeholders throughout the East Coast, he said.
"We acknowledge that some concerns have been expressed by members of the public. We listen to those concerns and take them seriously. We have been engaged with stakeholders for many years now and overall have received tremendous support from people on the East Coast. We have worked hard to be open and transparent and to provide factual information related to our operations. We will methodically carry out all work to the highest safety and environmental standards, while striving to leave the smallest footprint possible as we have done in Taranaki for over 10 years now."
Weber farmer, Donald James said too few had been consulted - which was "reprehensible".
"I want people to know how we were treated out here at Mangatuna when the TAG/Apache consortium went out of their way to get consents in place without consulting with people up the road."
Mr James said opponents to oil exploration had not given up and he wanted to educate people in other areas as to how they could thwart oil companies.
"If this becomes a productive well, it'll be the first of many and the fight is only beginning," he said.
"TAG have said they won't frack that well, how will we know what they find and can we take their word for it? Probably not. However, one Horizons Regional councillor has guaranteed me any resource application for fracking will be notified," he said.
TAG Oil is targeting the Waipawa Black Shale and Whangai geological formations using a rig from the company's successful Sidewinder gas and oil field in the Taranaki Basin. The rig would return to Taranaki as soon as the well was complete and analysis of samples began.
Mr James said he had information that oil companies were going to carrying out seismic tests in the Esk Valley in Hawke's Bay, the Napier/Taihape area and at Mahia.
"I've talked to people in those areas and they have no idea what's happening. But it's going to happen. I've been told oil company personnel have been staying at the motor camp at Mahia. People need to be informed, because information is power. If residents along a road or a valley decide they don't want the oil companies to come in and do a seismic survey's then that's the time when it could be stopped. You have to negotiate before the testing.
"I don't want others to be like us down here. We were lambs to the slaughter really."
Mr James, Sarah Roberts (an affected landowner from the Taranaki) Tom Burgess and Filipa Hope from Hawke's Bay, are speaking at a public meeting in Dannevirke on Saturday at The Hub at 2pm.
Mr James is joining members of Frack Free Tararua at a protest meeting today at the Tararua District Council's monthly meeting.
"We won't be allowed to speak, but we'll make our presence felt," he said. "We're very disappointed with our local council. A significant oil find could see towns like Dannevirke lose out, not gain."
A government report released last month said East Coast communities would be boosted by $2 billion annually if an oil and gas industry similar to Taranaki's was developed.